# Horizontal sundial calculations

Horizontal sundial calculations
You are encouraged to solve this task according to the task description, using any language you may know.

Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.

For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), with a legal meridian of 150°W.

(Note: the "meridian" is approximately the same concept as the "longitude" - the distinction is that the meridian is used to determine when it is "noon" for official purposes. This will typically be slightly different from when the sun appears at its highest location, because of the structure of time zones. For most, but not all, time zones (hour wide zones with hour zero centred on Greenwich), the legal meridian will be an even multiple of 15 degrees.)

Wikipedia: A sundial is a device that measures time by the position of the Sun. In common designs such as the horizontal sundial, the sun casts a shadow from its style (also called its Gnomon, a thin rod or a sharp, straight edge) onto a flat surface marked with lines indicating the hours of the day (also called the dial face or dial plate). As the sun moves across the sky, the shadow-edge progressively aligns with different hour-lines on the plate. Such designs rely on the style being aligned with the axis of the Earth's rotation. Hence, if such a sundial is to tell the correct time, the style must point towards true north (not the north or south magnetic pole) and the style's angle with horizontal must equal the sundial's geographical latitude.

## 11l

Translation of: Python
```V lat = Float(input(‘Enter latitude       => ’))
V lng = Float(input(‘Enter longitude      => ’))
V ref = Float(input(‘Enter legal meridian => ’))
print()

print(‘    sine of latitude:   #.3’.format(slat))
print(‘    diff longitude:     #.3’.format(lng - ref))
print()
print(‘Hour, sun hour angle, dial hour line angle from 6am to 6pm’)

L(h) -6 .. 6
V hra = 15.0 * h
hra -= lng - ref
V hla = degrees(atan(slat * tan(radians(hra))))
print(‘HR=#3; HRA=#3.3; HLA=#3.3’.format(h, hra, hla))```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA=-89.500; HLA= 84.225
HR= -5; HRA=-74.500; HLA= 17.283
HR= -4; HRA=-59.500; HLA=  8.334
HR= -3; HRA=-44.500; HLA=  4.847
HR= -2; HRA=-29.500; HLA=  2.795
HR= -1; HRA=-14.500; HLA=  1.278
HR=  0; HRA=  0.500; HLA= -0.043
HR=  1; HRA= 15.500; HLA= -1.371
HR=  2; HRA= 30.500; HLA= -2.910
HR=  3; HRA= 45.500; HLA= -5.018
HR=  4; HRA= 60.500; HLA= -8.671
HR=  5; HRA= 75.500; HLA=-18.451
HR=  6; HRA= 90.500; HLA= 84.225
```

Translation of: ALGOL 68

```with Ada.Text_IO;
procedure Sundial is
package Float_IO is new Ada.Text_IO.Float_IO (Float);

Latitude, Longitude, Meridian : Float;
Latitude_Sine                 : Float;
begin
Float_IO.Get (Latitude);
Float_IO.Get (Longitude);
Float_IO.Get (Meridian);

Latitude_Sine := Sin (Latitude * Pi / 180.0);
("   sine of latitude:" & Float'Image (Latitude_Sine));
("   diff longitude:" & Float'Image (Longitude - Meridian));

("hour, sun hour angle, dial hour line angle from 6am to 6pm");
for H in -6 .. 6 loop
declare
Hour_Angle : constant Float :=
15.0 * Float (H) - (Longitude - Meridian);
Line_Angle : constant Float :=
Arctan (Latitude_Sine * Tan (Hour_Angle * Pi / 180.0)) * 180.0 /
Pi;
begin
("HR=" &
Integer'Image (H) &
"; HRA=" &
Float'Image (Hour_Angle) &
"; HLA=" &
Float'Image (Line_Angle));
end;
end loop;
end Sundial;
```
Output:
```Enter latitude:       -4.95
Enter longitude:      -150.5
Enter legal meridian: -150

sine of latitude:-8.62864E-02
diff longitude:-5.00000E-01

hour, sun hour angle, dial hour line angle from 6am to 6pm
HR=-6; HRA=-8.95000E+01; HLA= 8.42248E+01
HR=-5; HRA=-7.45000E+01; HLA= 1.72829E+01
HR=-4; HRA=-5.95000E+01; HLA= 8.33371E+00
HR=-3; HRA=-4.45000E+01; HLA= 4.84671E+00
HR=-2; HRA=-2.95000E+01; HLA= 2.79487E+00
HR=-1; HRA=-1.45000E+01; HLA= 1.27835E+00
HR= 0; HRA= 5.00000E-01; HLA=-4.31443E-02
HR= 1; HRA= 1.55000E+01; HLA=-1.37079E+00
HR= 2; HRA= 3.05000E+01; HLA=-2.90964E+00
HR= 3; HRA= 4.55000E+01; HLA=-5.01802E+00
HR= 4; HRA= 6.05000E+01; HLA=-8.67140E+00
HR= 5; HRA= 7.55000E+01; HLA=-1.84510E+01
HR= 6; HRA= 9.05000E+01; HLA= 8.42248E+01```

## ALGOL 68

Works with: ALGOL 68 version Revision 1 - no extensions to language used
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny
Works with: ELLA ALGOL 68 version Any (with appropriate job cards) - tested with release 1.8-8d

Example extracted - with permission for a GPL - from Simon Wheaton-Smith's Illustrating Time's Shadow web page.

```BEGIN
REAL lat, slat, lng, ref;
print ( "Enter latitude       => " ); read (lat);
print ( "Enter longitude      => " ); read (lng);
print ( "Enter legal meridian => " ); read (ref);
new line(stand out);

slat := sin(lat*2*pi/360) ;
print ( ("    sine of latitude:   ", float(slat,8,2,1), new line ) );
print ( ("    diff longitude:     ", fixed((lng - ref),0,3), new line, new line ) );

print ( ("Hour, sun hour angle, dial hour line angle from 6am to 6pm", new line ));

FOR h FROM -6 TO 6
DO
REAL hra , hla ;              # define hour angle and hour line angle #
hra := 15 * h ;               # hour angle is 15 times the hour #
hra := hra - (lng - ref);     # but correct for longitude difference #
hla := arc tan ( slat * tan(hra*2*pi/360) ) * 360 / ( 2*pi) ;
# page 132 of a68gdoc.pdf documentationfile #
print ("HR="+whole(h,3)+"; HRA="+fixed(hra,8,3)+"; HLA="+fixed(hla,8,3));
new line(stand out)
OD
END```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -86.3e-3
diff longitude:     -.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.500; HLA= +84.225
HR= -5; HRA= -74.500; HLA= +17.283
HR= -4; HRA= -59.500; HLA=  +8.334
HR= -3; HRA= -44.500; HLA=  +4.847
HR= -2; HRA= -29.500; HLA=  +2.795
HR= -1; HRA= -14.500; HLA=  +1.278
HR= +0; HRA=  +0.500; HLA=  -0.043
HR= +1; HRA= +15.500; HLA=  -1.371
HR= +2; HRA= +30.500; HLA=  -2.910
HR= +3; HRA= +45.500; HLA=  -5.018
HR= +4; HRA= +60.500; HLA=  -8.671
HR= +5; HRA= +75.500; HLA= -18.451
HR= +6; HRA= +90.500; HLA= +84.225
```

## Arturo

Translation of: Nim
```degToRad: function [deg]-> deg * pi // 180

lat: to :floating input "Enter latitude       => "
lng: to :floating input "Enter longitude      => "
med: to :floating input "Enter legal meridian => "
print ""

print "    sine of latitude:   " ++ to :string .format:".3f" slat
print "    diff longitude:     " ++ to :string .format:".3f" lng-med
print ""
print "Hour, sun hour angle, dial hour line angle from 6am to 6pm"

loop (neg 6)..6 'h [
hra: med + (to :floating 15*h) - lng
print "HR=" ++ (to :string .format:"3d" h) ++ "; " ++
"HRA=" ++ (to :string .format:"7.3f" hra) ++ "; " ++
"HLA=" ++ (to :string .format:"7.3f" hla)
]
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA=-89.500; HLA= 84.225
HR= -5; HRA=-74.500; HLA= 17.283
HR= -4; HRA=-59.500; HLA=  8.334
HR= -3; HRA=-44.500; HLA=  4.847
HR= -2; HRA=-29.500; HLA=  2.795
HR= -1; HRA=-14.500; HLA=  1.278
HR=  0; HRA=  0.500; HLA= -0.043
HR=  1; HRA= 15.500; HLA= -1.371
HR=  2; HRA= 30.500; HLA= -2.910
HR=  3; HRA= 45.500; HLA= -5.018
HR=  4; HRA= 60.500; HLA= -8.671
HR=  5; HRA= 75.500; HLA=-18.451
HR=  6; HRA= 90.500; HLA= 84.225```

## AutoHotkey

 This example is incorrect. Please fix the code and remove this message.Details: 6AM,5AM,4AM,3AM,2AM,1AM,0PM - use hour+12 instead of abs(hour), I suspect
Translation of: F#

AutoHotkey is not a command-line programming language, let me make that clear. However, in translating the F# I found that the command line really is best for this type of app. The first 3 comments in the script describe the workarounds used to interface with the commandline.

```DllCall("AllocConsole")  ; Open a console window for this application
Pi := 4*ATan(1)
,Degrees := Pi/180

FileAppend, Enter Latitude: , CONOUT\$ ; write to  stdout

FileAppend, Enter Longitude: , CONOUT\$

FileAppend, Enter Legal meridian: , CONOUT\$

sineLatitude := Sin(latitude*Degrees)
FileAppend, `n, CONOUT\$
FileAppend, Sine of latitude: %sineLatitude%`n, CONOUT\$
FileAppend, % "Difference of Longitudes (given longitude - meridian): " . longitude-meridian . "`n", CONOUT\$
FileAppend, `n, CONOUT\$

FileAppend, Numbers from 6 AM to 6 PM:`n, CONOUT\$
FileAppend, Hour`t`tSun Hour Angle`t Dial hour line angle`n, CONOUT\$

hour := -7
While (++hour < 7)
{
clockHour := hour < 0 ? abs(hour) . "AM" : hour . "PM"
shr := RTrim("" . (15.0*hour - (longitude-meridian)), "0") ; RTrim() removes trailing zeroes
dhla := Atan(sineLatitude*Tan(shr*degrees))/Degrees
FileAppend, %clockhour%`t`t%shr%`t`t%dhla%`n, CONOUT\$
}
MsgBox close me when done.
```
Output:
```Enter Latitude:-4.95
Enter Longitude:-150.5
Enter Legal meridian:-150

Sine of latitude: -0.086286
Difference of Longitudes (given longitude - meridian): -0.500000

Numbers from 6 AM to 6 PM:
Hour            Sun Hour Angle   Dial hour line angle
6AM             -89.5           84.224833
5AM             -74.5           17.282934
4AM             -59.5           8.333712
3AM             -44.5           4.846709
2AM             -29.5           2.794874
1AM             -14.5           1.278353
0PM             0.5             -0.043144
1PM             15.5            -1.370788
2PM             30.5            -2.909643
3PM             45.5            -5.018023
4PM             60.5            -8.671397
5PM             75.5            -18.450999
6PM             90.5            84.224833```

## AWK

```# syntax: GAWK -f HORIZONTAL_SUNDIAL_CALCULATIONS.AWK
BEGIN {
printf("enter latitude (degrees): ") ; getline latitude
printf("enter longitude (degrees): ") ; getline longitude
printf("enter legal meridian (degrees): ") ; getline meridian
printf("\nhour  sun hour angle  dial hour line angle\n")
slat = sin(dr(latitude))
for (hour=-6; hour<=6; hour++) { # 6AM-6PM
hra = 15 * hour - longitude + meridian
printf("%4d %15.3f %21.3f\n",hour+12,hra,hla)
}
exit(0)
}
function dr(x) { return x * 3.14159265 / 180 } # degrees to radians
function rd(x) { return x * 180 / 3.14159265 } # radians to degrees
```

output:

```enter latitude (degrees): -4.95
enter longitude (degrees): -150.5
enter legal meridian (degrees): -150

hour  sun hour angle  dial hour line angle
6         -89.500                84.225
7         -74.500                17.283
8         -59.500                 8.334
9         -44.500                 4.847
10         -29.500                 2.795
11         -14.500                 1.278
12           0.500                -0.043
13          15.500                -1.371
14          30.500                -2.910
15          45.500                -5.018
16          60.500                -8.671
17          75.500               -18.451
18          90.500               -95.775
```

## BASIC

### ANSI BASIC

Translation of: ALGOL-68 – ANSI BASIC has a possibility to use degrees in calculations.
Works with: Decimal BASIC
```100 REM Horizontal sundial calculations
110 INPUT PROMPT "Enter latitude       => ": Lat
120 INPUT PROMPT "Enter longitude      => ": Lng
130 INPUT PROMPT "Enter legal meridian => ": Ref
140 PRINT
150 OPTION ANGLE DEGREES
160 LET Slat = SIN(Lat)
170 PRINT "    sine of latitude:   "; Slat
180 PRINT "    diff longitude:     "; Lng - Ref
190 PRINT
200 PRINT "Hour, sun hour angle, dial hour line angle from 6am to 6pm"
210 FOR Hour = -6 TO 6
220    LET HourAngle = 15 * Hour
230    LET HourAngle = HourAngle - (Lng - Ref) ! correct for longitude difference
240    LET HourLineAngle = ATN(Slat * TAN(HourAngle))
250    PRINT USING "HR=###; HRA=####.###; HLA=####.###": Hour, HourAngle, HourLineAngle
260 NEXT Hour
270 END
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -8.62863657979234E-2
diff longitude:     -.5

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.500; HLA=  84.225
HR= -5; HRA= -74.500; HLA=  17.283
HR= -4; HRA= -59.500; HLA=   8.334
HR= -3; HRA= -44.500; HLA=   4.847
HR= -2; HRA= -29.500; HLA=   2.795
HR= -1; HRA= -14.500; HLA=   1.278
HR=  0; HRA=    .500; HLA=   -.043
HR=  1; HRA=  15.500; HLA=  -1.371
HR=  2; HRA=  30.500; HLA=  -2.910
HR=  3; HRA=  45.500; HLA=  -5.018
HR=  4; HRA=  60.500; HLA=  -8.671
HR=  5; HRA=  75.500; HLA= -18.451
HR=  6; HRA=  90.500; HLA=  84.225
```

### BASIC256

```call SolarhoraAngle(-4.95, -150.5, -150.0)
end

return theta * 180 / pi
end function

return theta * pi / 180
end function

function sign(x)
if x < 0 then sign = -1
if x > 0 then sign = 1
if x = 0 then sign = 0
end function

subroutine SolarhoraAngle(latitude, longitude, meridian)
print "Latitude  = "; latitude
print "Longitude = "; longitude
print "Meridian  = "; meridian
print
print "sine of latitude: "; sin(latitude * pi / 180)
print "  diff longitude: "; longitude - meridian
print
print " Time    Sun hora angle  Dial hora line angle"
for hora = 6 to 18
hra = (15 * hora) - longitude + meridian - 180
if abs(hra) > 90 then hla += 180 * sign(hra * latitude)
if hora > 12 then time = hora - 12 : ap\$ = " p.m." else time = hora : ap\$ = " a.m."
print time; ap\$; chr(9); hra; chr(9); chr(9); hla
next hora
end subroutine```

### BBC BASIC

```      INSTALL @lib\$+"FNUSING"

INPUT "Enter latitude (degrees)      : " latitude
INPUT "Enter longitude (degrees)     : " longitude
INPUT "Enter legal meridian (degrees): " meridian

PRINT '" Time", "Sun hour angle", "Dial hour line angle"

FOR hour = 6 TO 18
hra = 15*hour - longitude + meridian - 180
IF ABS(hra) > 90 hla += 180 * SGN(hra * latitude)
PRINT FNusing("##.##", hour), FNusing("  ####.###  ", hra), FNusing("  ####.###", hla)
NEXT hour
```
Output:

(note the correct negative value for time 18:00)

```Enter latitude (degrees)      : -4.95
Enter longitude (degrees)     : -150.5
Enter legal meridian (degrees): -150.0

Time     Sun hour angle      Dial hour line angle
6.00        -89.500              84.225
7.00        -74.500              17.283
8.00        -59.500               8.334
9.00        -44.500               4.847
10.00        -29.500               2.795
11.00        -14.500               1.278
12.00          0.500              -0.043
13.00         15.500              -1.371
14.00         30.500              -2.910
15.00         45.500              -5.018
16.00         60.500              -8.671
17.00         75.500             -18.451
18.00         90.500             -95.775```

### Chipmunk Basic

Works with: Chipmunk Basic version 3.6.4
```10 CLS
20 DEF FNR(x) = x * PI/180
30 DEF FND(x) = x * 180/PI
40 INPUT "      Enter latitude (degrees): ";latitude
50 INPUT "     Enter longitude (degrees): ";longitude
60 INPUT "Enter legal meridian (degrees): ";meridian
70 PRINT
80 PRINT " Time  Sun hour angle  Dial hour line angle"
90 FOR h = 6 TO 18
100 hra = 15*h-longitude+meridian-180
110 hla = FN D(ARCTAN(SIN(FN R(latitude))*TAN(FN R(hra))))
120 IF ABS(hra) > 90 THEN hla = hla+180*SGN(hra*latitude)
130 PRINT USING "##.##";h;TAB (10)
140 PRINT USING "####.###";hra;TAB (27)
150 PRINT USING "####.###";hla
160 NEXT h
170 END
```
Output:
`Same as FreeBASIC entry.`

### FreeBASIC

Translation of: BBC BASIC
```' version 04-11-2016
' compile with: fbc -s console

(x) * Atn(1) / 45
#EndMacro

(x) * 45 / Atn(1)
#EndMacro

' ------=< MAIN >=------

Dim As Double latitude, longitude, meridian, hra, hla
Dim As ULong h

Input "      Enter latitude (degrees): ", latitude
Input "     Enter longitude (degrees): ", longitude
Input "Enter legal meridian (degrees): ", meridian

Print
Print " Time  Sun hour angle  Dial hour line angle"

For h = 6 To 18
hra = h * 15 - longitude + meridian - 180
If Abs(hra) > 90 Then hla += 180 * Sgn(hra * latitude)
Print Using "##.##     ####.###         ####.###"; h; hra; hla
Next

' empty keyboard buffer
While InKey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End```
Output:
```      Enter latitude (degrees): -4.95
Enter longitude (degrees): -150.5
Enter legal meridian (degrees): -150

Time  Sun hour angle  Dial hour line angle
6.00      -89.500           84.225
7.00      -74.500           17.283
8.00      -59.500            8.334
9.00      -44.500            4.847
10.00      -29.500            2.795
11.00      -14.500            1.278
12.00        0.500           -0.043
13.00       15.500           -1.371
14.00       30.500           -2.910
15.00       45.500           -5.018
16.00       60.500           -8.671
17.00       75.500          -18.451
18.00       90.500          -95.775```

### FutureBasic

```window 1

def fn rad2deg( theta as double ) as double = theta * 180 / pi
def fn deg2rad( theta as double ) as double = theta * pi / 180

local fn SolarHourAngle( latitude as double, longitude as double, meridian as double )
long        hour
double      hra, hla, t
CFStringRef ap

print "Latitude  = "; latitude; chr\$(13); "Longitude = "; longitude; chr\$(13); "Meridian  = "; meridian
print : print "sine of latitude: "; sin(latitude * pi / 180 ); chr\$(13); "  diff longitude: "; longitude - meridian
print : print "Time", "Sun hour angle", "Dial hour line angle"
for hour = 6 to 18
hra = ( 15 * hour ) - longitude + meridian - 180
hla = fn rad2deg( atn( sin( fn deg2rad( latitude ) ) * tan( fn deg2rad( hra ) )))
if abs( hra ) > 90 then hla = hla + 180 * sgn( hra * latitude )
if hour > 12 then t = hour - 12 : ap = @" a.m." else t = hour : ap = @" p.m."
print using "##"; t; ap, using "####.##"; hra, using "####.###"; hla
next hour
end fn

fn SolarHourAngle( -4.95, -150.5, -150.0 )

HandleEvents```

Output:

```Latitude  = -4.95
Longitude = -150.5
Meridian  = -150

sine of latitude: -0.0862863658
diff longitude: -0.5

Time            Sun hour angle  Dial hour line angle
6 p.m.          -89.50           84.225
7 p.m.          -74.50           17.283
8 p.m.          -59.50            8.334
9 p.m.          -44.50            4.847
10 p.m.          -29.50            2.795
11 p.m.          -14.50            1.278
12 p.m.            0.50           -0.043
1 a.m.           15.50           -1.371
2 a.m.           30.50           -2.910
3 a.m.           45.50           -5.018
4 a.m.           60.50           -8.671
5 a.m.           75.50          -18.451
6 a.m.           90.50          -95.775
```

### GW-BASIC

Translation of: ALGOL 68
Works with: PC-BASIC version any
```10  ' Horizontal sundial calculations
20  PRINT "Enter latitude       => ";
30  INPUT LAT
40  PRINT "Enter longitude      => ";
50  INPUT LNG
60  PRINT "Enter legal meridian => ";
70  INPUT REF
80  PRINT
90  LET PI = 4 * ATN(1)
100 LET SLAT = SIN(LAT * PI / 180)
110 PRINT "    sine of latitude:   "; USING "#.##^^^^"; SLAT
120 PRINT "    diff longitude:     "; USING "####.###"; LNG - REF
130 PRINT
140 PRINT "Hour, sun hour angle, dial hour line angle from 6am to 6pm"
150 FOR H% = -6 TO 6
160  LET HRA = 15 * H%
170  LET HRA = HRA - (LNG - REF): ' correct for longitude difference
180  LET HLA = ATN(SLAT * TAN(HRA * PI / 180)) * 180 / PI
190  PRINT "HR="; USING "+##"; H%;
200  PRINT "; HRA="; USING "+###.###"; HRA;
210  PRINT "; HLA="; USING "+###.###"; HLA
220 NEXT H%
230 END
```
Output:
```Enter latitude       => ? -4.95
Enter longitude      => ? -150.5
Enter legal meridian => ? -150

sine of latitude:   -.86E-01
diff longitude:       -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.500; HLA= +84.225
HR= -5; HRA= -74.500; HLA= +17.283
HR= -4; HRA= -59.500; HLA=  +8.334
HR= -3; HRA= -44.500; HLA=  +4.847
HR= -2; HRA= -29.500; HLA=  +2.795
HR= -1; HRA= -14.500; HLA=  +1.278
HR= +0; HRA=  +0.500; HLA=  -0.043
HR= +1; HRA= +15.500; HLA=  -1.371
HR= +2; HRA= +30.500; HLA=  -2.910
HR= +3; HRA= +45.500; HLA=  -5.018
HR= +4; HRA= +60.500; HLA=  -8.671
HR= +5; HRA= +75.500; HLA= -18.451
HR= +6; HRA= +90.500; HLA= +84.225
```

### IS-BASIC

```100 PROGRAM "SunDial.bas"
120 TEXT 80
130 LET DR=PI/180:LET RD=180/PI
140 INPUT PROMPT "Enter latitude:  ":LAT
150 INPUT PROMPT "Enter longitude: ":LNG
160 INPUT PROMPT "Enter legal meridian: ":REF
170 LET S=SIN(LAT*DR)
180 PRINT :PRINT "Sine of latitude :";S
190 PRINT "Diff longitude: ";LNG-REF
200 PRINT " Hour,",,"sun hour angle, dial hour line angle from 6am to 6 pm"
210 FOR H=6 TO 18
220   LET HRA=15*H-LNG+REF
230   LET HLA=ATN(S*TAN(HRA*DR))*RD
240   PRINT "HR = ";H,"HRA =";HRA,"HLA =";HLA
250 NEXT```

### Liberty BASIC

Based on Algol & BBC BASIC versions. Note Liberty BASIC works in radians.

```global pi
pi = 3.14159265
input "Enter latitude  (degrees)     : "; latitude      '     -4.95
input "Enter longitude (degrees)     : "; longitude     '   -150.5
input "Enter legal meridian (degrees): "; meridian      '   -150.0
print
print "Time       Sun hour angle   Dial hour line angle"
for hour = 6 TO 18
hra = 15 * hour - longitude + meridian - 180
if abs(hra) > 90 then hla = hla + 180 * sgn(hra * latitude)
print using( "##.##", hour), using("####.###  ", hra), using("####.###", hla)
next hour
end

rad2deg = theta * 180 / pi
end function

deg2rad = theta * pi / 180
end function

function sgn(x)
if x > 0 then sgn = 1 else sgn = -1
end function```
Output:
```Enter latitude  (degrees)     : -4.95
Enter longitude (degrees)     : -150.5
Enter legal meridian (degrees): -150.0

Time       Sun hour angle   Dial hour line angle
6.00          -89.500        84.225
7.00          -74.500        17.283
8.00          -59.500         8.334
9.00          -44.500         4.847
10.00          -29.500         2.795
11.00          -14.500         1.278
12.00            0.500        -0.043
13.00           15.500        -1.371
14.00           30.500        -2.910
15.00           45.500        -5.018
16.00           60.500        -8.671
17.00           75.500       -18.451
18.00           90.500       -95.775
```

### Microsoft Small Basic

Translation of: ALGOL-68
```TextWindow.Write("Enter latitude       => ")
TextWindow.Write("Enter longitude      => ")
TextWindow.Write("Enter legal meridian => ")
TextWindow.WriteLine("")
TextWindow.Write("    sine of latitude:   ")
TextWindow.WriteLine(Math.Round(sLat * 10000) / 10000)
TextWindow.Write("    diff longitude:     ")
TextWindow.WriteLine(lng - ref)
TextWindow.WriteLine("")
TextWindow.WriteLine("Hour, sun hour angle, dial hour line angle from 6am to 6pm")
For hour = -6 To 6
hourAngle = 15 * hour
hourAngle = hourAngle - (lng - ref) ' correct for longitude difference
TextWindow.Write("HR=")
TextWindow.CursorLeft = 3 + (3 - Text.GetLength(hour))
TextWindow.Write(hour)
TextWindow.Write("; HRA=")
TextWindow.CursorLeft = 12 + (6 - Text.GetLength(hourAngle))
TextWindow.Write(hourAngle)
TextWindow.Write("; HLA=")
TextWindow.CursorLeft = 24 + (4 - Text.GetLength(Math.Floor(hourLineAngle)))
TextWindow.Write(Math.Round(hourLineAngle * 1000) / 1000)
TextWindow.WriteLine("")
EndFor```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.0863
diff longitude:     -0.5

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.5; HLA=  84.225
HR= -5; HRA= -74.5; HLA=  17.283
HR= -4; HRA= -59.5; HLA=   8.334
HR= -3; HRA= -44.5; HLA=   4.847
HR= -2; HRA= -29.5; HLA=   2.795
HR= -1; HRA= -14.5; HLA=   1.278
HR=  0; HRA=   0.5; HLA=  -0.043
HR=  1; HRA=  15.5; HLA=  -1.371
HR=  2; HRA=  30.5; HLA=  -2.91
HR=  3; HRA=  45.5; HLA=  -5.018
HR=  4; HRA=  60.5; HLA=  -8.671
HR=  5; HRA=  75.5; HLA= -18.451
HR=  6; HRA=  90.5; HLA=  84.225
```

### Minimal BASIC

Works with: QBasic
Translation of: ALGOL-68
```10 REM Horizontal sundial calculations
20 DEF FNM(X) = INT(X*1000+0.5)/1000
30 PRINT "Enter latitude";
40 INPUT L
50 PRINT "Enter longitude";
60 INPUT L1
70 PRINT "Enter legal meridian";
80 INPUT R
90 PRINT
100 LET P = 4*ATN(1)
110 LET S1 = SIN(L*P/180)
120 PRINT "    sine of latitude:"; S1
130 PRINT "    diff longitude:  "; FNM(L1-R)
140 PRINT
150 PRINT "Hour, sun hour angle, dial hour line angle from 6am to 6pm"
160 FOR H = -6 TO 6
170 LET A1 = 15*H
180 REM Correct for longitude difference:
190 LET A1 = A1-(L1-R)
200 LET A2 = ATN(S1*TAN(A1*P/180))*180/P
210 PRINT "HR ="; H;
220 PRINT TAB(9); "HRA ="; FNM(A1);
230 PRINT TAB(24); "HLA ="; FNM(A2)
240 NEXT H
250 END```

### PureBasic

Translation of: ALGOL 68
```If OpenConsole()
Define.f lat, slat, lng, ref
Define.i h
Print("Enter latitude       => "): lat=ValF(Input())
Print("Enter longitude      => "): lng=ValF(Input())
Print("Enter legal meridian => "): ref=ValF(Input())
PrintN("")

slat=Sin(lat*2*#PI/360)
PrintN("    sine of latitude:   "+StrF(slat,3))
PrintN("    diff longitude:     "+StrF((lng-ref),3)+#CRLF\$)
PrintN("Hour, sun hour angle, dial hour line angle from 6am to 6pm")

For h=-6 To 6
Define.f hra, hla
hra=15*h
hra=hra-(lng-ref)
hla=ATan(slat*Tan(hra*2*#PI/360))*360/(2*#PI)
PrintN("HR="+RSet(Str(h),3)+"; HRA="+RSet(StrF(hra,3),7)+"; HLA="+RSet(StrF(hla,3),7))
Next

EndIf```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA=-89.500; HLA= 84.225
HR= -5; HRA=-74.500; HLA= 17.283
HR= -4; HRA=-59.500; HLA=  8.334
HR= -3; HRA=-44.500; HLA=  4.847
HR= -2; HRA=-29.500; HLA=  2.795
HR= -1; HRA=-14.500; HLA=  1.278
HR=  0; HRA=  0.500; HLA= -0.043
HR=  1; HRA= 15.500; HLA= -1.371
HR=  2; HRA= 30.500; HLA= -2.910
HR=  3; HRA= 45.500; HLA= -5.018
HR=  4; HRA= 60.500; HLA= -8.671
HR=  5; HRA= 75.500; HLA=-18.451
HR=  6; HRA= 90.500; HLA= 84.225
```

### Run BASIC

```global pi
pi = 22 / 7

print "Enter latitude  (degrees)     : "; :input latitude      '    -4.95
print "Enter longitude (degrees)     : "; :input longitude     '   -150.5
print "Enter legal meridian (degrees): "; :input meridian      '   -150.0

print
print "Time     Sun hour angle   Dial hour line angle"

for hour = 6 TO 18
hra = (15 * hour) - longitude + meridian -180
if abs( hra) >90 then hla =hla +180 *sgn( hra *latitude)
print using( "##", hour);"         ";using("####.##", hra);"         ";using("####.###", hla)
next hour

end function

end function

function sgn( x)
if x >0 then sgn =1 else sgn =-1
end function
end```
Output:
```Enter latitude: -4.95
Enter longitude: -150.5
Enter legal meridian: -150

Time     Sun hour angle   Dial hour line angle
6          -89.50           84.606
7          -74.50           17.316
8          -59.50            8.342
9          -44.50            4.850
10          -29.50            2.796
11          -14.50            1.279
12            0.50           -0.043
13           15.50           -1.371
14           30.50           -2.911
15           45.50           -5.021
16           60.50           -8.680
17           75.50          -18.488
18           90.50          -96.224```

### True BASIC

```FUNCTION rad2deg(theta)
END FUNCTION
END FUNCTION
FUNCTION signo(x)
IF x > 0 THEN LET signo = 1 ELSE LET signo = -1
END FUNCTION
INPUT prompt "Enter latitude  (degrees)     : ": latitude  !    -4.95
INPUT prompt "Enter longitude (degrees)     : ": longitude !   -150.5
INPUT prompt "Enter legal meridian (degrees): ": meridian  !   -150.0
PRINT
PRINT "Time     Sun hora angle   Dial hora line angle"
FOR hora = 6 TO 18
LET hra = (15*hora)-longitude+meridian-180
IF abs(hra) > 90 THEN LET hla = hla+180*signo(hra*latitude)
PRINT  USING "##         ####.##         ####.###": hora, hra, hla
NEXT hora
END
```

### XBasic

Translation of: ALGOL-68
Works with: Windows XBasic
```PROGRAM "sundial"
VERSION "0.0001"

IMPORT "xma"

DECLARE FUNCTION Entry()

FUNCTION Entry()
lat! = SINGLE(INLINE\$("Enter latitude       => "))
lng! = SINGLE(INLINE\$("Enter longitude      => "))
ref! = SINGLE(INLINE\$("Enter legal meridian => "))
PRINT
slat! = SIN(lat! * \$\$PI / 180.0)
PRINT "    sine of latitude:   "; FORMAT\$("#.##^^^^", slat!)
PRINT "    diff longitude:     "; FORMAT\$("#.###", lng! - ref!)
PRINT
PRINT "Hour, sun hour angle, dial hour line angle from 6am to 6pm"
FOR hour@ = -6 TO 6
hourAngle! = 15 * hour@
hourAngle! = hourAngle! - (lng! - ref!) ' correct for longitude difference
hourLineAngle! = ATAN(slat! * TAN(hourAngle! * \$\$PI / 180.0)) * 180.0 / \$\$PI
PRINT "HR="; FORMAT\$("###", hour@);
PRINT "; HRA="; FORMAT\$("####.###", hourAngle!);
PRINT "; HLA="; FORMAT\$("####.###", hourLineAngle!)
NEXT hour@
END FUNCTION
END PROGRAM```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -8.63E-02
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.500; HLA=  84.225
HR= -5; HRA= -74.500; HLA=  17.283
HR= -4; HRA= -59.500; HLA=   8.334
HR= -3; HRA= -44.500; HLA=   4.847
HR= -2; HRA= -29.500; HLA=   2.795
HR= -1; HRA= -14.500; HLA=   1.278
HR=  0; HRA=   0.500; HLA=  -0.043
HR=  1; HRA=  15.500; HLA=  -1.371
HR=  2; HRA=  30.500; HLA=  -2.910
HR=  3; HRA=  45.500; HLA=  -5.018
HR=  4; HRA=  60.500; HLA=  -8.671
HR=  5; HRA=  75.500; HLA= -18.451
HR=  6; HRA=  90.500; HLA=  84.225
```

### Yabasic

```SolarHourAngle(-4.95, -150.5, -150.0)
end

return theta * 180 / pi
end sub

return theta * pi / 180
end sub

sub SolarHourAngle(latitude, longitude, meridian)
local long, hour, hra, hla, time, ap\$

print "Latitude  = ", latitude
print "Longitude = ", longitude
print "Meridian  = ", meridian
print "\nsine of latitude: ", sin(latitude * pi / 180)
print "  diff longitude: ", longitude - meridian
print "\n Time    Sun hour angle  Dial hour line angle"
for hour = 6 to 18
hra = (15 * hour) - longitude + meridian - 180
if abs(hra) > 90  hla = hla + 180 * sig(hra * latitude)
if hour > 12 then time = hour - 12 : ap\$ = " a.m." else time = hour : ap\$ = " p.m." : fi
print time using "##", ap\$, chr\$(9), hra using "####.##", chr\$(9), chr\$(9), hla using "####.###"
next hour
end sub```

### ZX Spectrum Basic

Translation of: ERRE
```10 DEF FN r(x)=x*PI/180
20 DEF FN d(x)=x*180/PI
30 INPUT "Enter latitude (degrees): ";latitude
40 INPUT "Enter longitude (degrees): ";longitude
50 INPUT "Enter legal meridian (degrees): ";meridian
60 PRINT "Latitude: ";latitude
70 PRINT "Longitude:";longitude
80 PRINT "Legal meridian: ";meridian
90 PRINT '"      Sun         Dial"
100 PRINT "Time  hour angle  hour line ang."
110 PRINT "________________________________"
120 FOR h=6 TO 18
130 LET hra=15*h-longitude+meridian-180
140 LET hla=FN d(ATN (SIN (FN r(latitude))*TAN (FN r(hra))))
150 IF ABS (hra)>90 THEN LET hla=hla+180*SGN (hra*latitude)
160 PRINT h;"    ";hra;"        ";hla
170 NEXT h```

## C

Translation of: ALGOL 68
```#include <stdio.h>
#include <math.h>

#define PICKVALUE(TXT, VM) do {			\
printf("%s: ", TXT);			\
scanf("%lf", &VM);				\
} while(0);

#if !defined(M_PI)
#define M_PI 3.14159265358979323846
#endif

#define DR(X) ((X)*M_PI/180.0)
#define RD(X) ((X)*180.0/M_PI)

int main()
{
double lat, slat, lng, ref;
int h;

PICKVALUE("Enter latitude", lat);
PICKVALUE("Enter longitude", lng);
PICKVALUE("Enter legal meridian", ref);
printf("\n");

slat = sin(DR(lat));
printf("sine of latitude: %.3f\n", slat);
printf("diff longitude: %.3f\n\n", lng - ref);

printf("Hour, sun hour angle, dial hour line angle from 6am to 6pm\n");

for(h = -6; h <= 6; h++)
{
double hla, hra;
hra = 15.0*h;
hra = hra - lng + ref;
hla = RD(atan(slat * tan(DR(hra))));
printf("HR= %3d;  \t  HRA=%7.3f;  \t  HLA= %7.3f\n",
h, hra, hla);
}

return 0;
}
```

## C#

```using System;

namespace RosettaCode
{
internal sealed class Program
{
private static void Main()
{
Func<double> getDouble = () => Convert.ToDouble(Console.ReadLine());
double h = 0, lat, lng, lme, slat, hra, hla;

Console.Write("Enter latitude       => ");
lat = getDouble();
Console.Write("Enter longitude      => ");
lng = getDouble();
Console.Write("Enter legal meridian => ");
lme = getDouble();

slat = Math.Sin(lat*2*Math.PI/360);
Console.WriteLine("\n    sine of latitude:   {0:0.000}", slat);
Console.WriteLine("    diff longitude:     {0:0.000}\n", lng-lme);
Console.WriteLine("Hour, sun hour angle, dial hour line angle from 6am to 6pm");
for (h = -6; h<6; h++)
{
hra = 15*h;
hra -= lng-lme;
hla = Math.Atan(slat*Math.Tan(hra*2*Math.PI/360))*360/(2*Math.PI);
Console.WriteLine("HR= {0,7:0.000}; HRA {1,7:0.000}; HLA= {2,7:0.000}", h, hra, hla);
}
}
}
}
```

## C++

```#include <cmath>
#include <iostream>
#include <numbers>

// constants used in the calculations
static const double DegreesPerHour = 15.0;
static const double DegreesPerRadian = 180.0 * std::numbers::inv_pi;

// a structure for the calculation results
struct SundialCalculation
{
double HourAngle;
double HourLineAngle;
};

// a class for a sundial at a location
class Sundial
{
// intermediate values used in the caclulations
double m_sinLatitude;
double m_timeZoneCorrection;

public:
Sundial(double latitude, double longitude, double legalMeridian) noexcept
, m_timeZoneCorrection(legalMeridian - longitude) {}

{
double hourAngle = hoursSinceNoon * DegreesPerHour + m_timeZoneCorrection;
return SundialCalculation {hourAngle, hourLineAngle};
}
};

int main()
{
double latitude, longitude, legalMeridian;
std::cout << "Enter latitude:";
std::cin >> latitude;
std::cout << "Enter longitude:";
std::cin >> longitude;
std::cout << "Enter legal meridian:";
std::cin >> legalMeridian;

// create a sundial at the user specified location
const Sundial sundial(latitude, longitude, legalMeridian);
for(int hour = -6; hour < 7; ++hour)
{
// cacluate the angles

// print the results
auto amOrPm = hour < 0 ? "am" : "pm";
auto hourString = std::to_string(hour < 1 ? 12 + hour : hour);
std::cout << hourString << amOrPm <<
" - sun hour angle:" << result.HourAngle <<
", dial hour line angle:" << result.HourLineAngle << "\n";
}
}
```
Output:
```Enter latitude:-4.95
Enter longitude:-150.5
Enter legal meridian:-150
6am - sun hour angle:-89.5, dial hour line angle:84.2248
7am - sun hour angle:-74.5, dial hour line angle:17.2829
8am - sun hour angle:-59.5, dial hour line angle:8.33371
9am - sun hour angle:-44.5, dial hour line angle:4.84671
10am - sun hour angle:-29.5, dial hour line angle:2.79487
11am - sun hour angle:-14.5, dial hour line angle:1.27835
12pm - sun hour angle:0.5, dial hour line angle:-0.0431443
1pm - sun hour angle:15.5, dial hour line angle:-1.37079
2pm - sun hour angle:30.5, dial hour line angle:-2.90964
3pm - sun hour angle:45.5, dial hour line angle:-5.01802
4pm - sun hour angle:60.5, dial hour line angle:-8.6714
5pm - sun hour angle:75.5, dial hour line angle:-18.451
6pm - sun hour angle:90.5, dial hour line angle:-95.7752
```

## COBOL

Works with: OpenCOBOL
```PROGRAM-ID. horizontal-sundial-calc.

DATA DIVISION.
WORKING-STORAGE SECTION.
01  latitude                       PIC S9(3)V9(5) COMP.
01  longitude                      PIC S9(3)V9(5) COMP.
01  legal-meridian                 PIC S9(3)V9(5) COMP.

01  lat-sine                       PIC S9(3)V9(5) COMP.
01  diff-longitude                 PIC S9(3)V9(5) COMP.

01  lat-sine-disp                  PIC -(3)9.9(5).
01  diff-longitude-disp            PIC -(3)9.9(5).

01  hour                           PIC S9 COMP.
01  sun-hour-angle                 PIC S9(3)V9(5) COMP.
01  dial-hour-line-angle           PIC S9(3)V9(5) COMP.

01  hour-disp                      PIC 99.
01  sun-hour-angle-disp            PIC -(3)9.9(5).
01  dial-hour-line-angle-disp      PIC -(3)9.9(5).

PROCEDURE DIVISION.
DISPLAY "Enter latitude: " NO ADVANCING
ACCEPT latitude
DISPLAY "Enter longitude: " NO ADVANCING
ACCEPT longitude
DISPLAY "Enter legal meridian: " NO ADVANCING
ACCEPT legal-meridian
DISPLAY SPACE

COMPUTE lat-sine, lat-sine-disp ROUNDED =
FUNCTION SIN(latitude * 2 * FUNCTION PI / 360)
DISPLAY "Sine of latitude: " FUNCTION TRIM(lat-sine-disp)

SUBTRACT legal-meridian FROM longitude
GIVING diff-longitude, diff-longitude-disp
DISPLAY "Diff longitude: " FUNCTION TRIM(diff-longitude-disp)
DISPLAY SPACE

DISPLAY "Time   Sun hour angle  Dial hour line angle"
PERFORM VARYING hour FROM -6 BY 1 UNTIL hour > 6
COMPUTE sun-hour-angle ROUNDED = hour * 15 - diff-longitude
COMPUTE dial-hour-line-angle ROUNDED = FUNCTION ATAN(lat-sine
* FUNCTION TAN(sun-hour-angle * 2 * FUNCTION PI / 360))
* 360 / (2 * FUNCTION PI)

ADD 12 TO hour GIVING hour-disp
MOVE sun-hour-angle TO sun-hour-angle-disp
MOVE dial-hour-line-angle TO dial-hour-line-angle-disp
DISPLAY hour-disp ":00 " sun-hour-angle-disp "      "
dial-hour-line-angle-disp
END-PERFORM
.
```
Output:
```Enter latitude: -4.95
Enter longitude: -150.5
Enter legal meridian: -150

Sine of latitude: -0.08629
Diff longitude: -0.50000

Time   Sun hour angle  Dial hour line angle
06:00  -89.50000        84.22441
07:00  -74.50000        17.28173
08:00  -59.50000         8.33311
09:00  -44.50000         4.84635
10:00  -29.50000         2.79467
11:00  -14.50000         1.27826
12:00    0.50000        -0.04314
13:00   15.50000        -1.37069
14:00   30.50000        -2.90943
15:00   45.50000        -5.01765
16:00   60.50000        -8.67077
17:00   75.50000       -18.44973
18:00   90.50000        84.22441
```

## D

Translation of: Python
```import std.stdio, std.math, std.conv, std.string;

double radians(in double x) pure nothrow { return x * (PI / 180); }
double degrees(in double x) pure nothrow { return x / (PI / 180); }

T input(T)(in string msg) {
msg.write;
}

void main() {
immutable lat = input!double("Enter latitude       => ");
immutable lng = input!double("Enter longitude      => ");
immutable lme = input!double("Enter legal meridian => ");
writeln;

writefln("    sine of latitude:   %.3f", slat);
writefln("    diff longitude:     %.3f", lng - lme);
writeln;
"Hour, sun hour angle, dial hour line angle from 6am to 6pm".writeln;

foreach (immutable h; -6 .. 7) {
immutable double hra = 15 * h - (lng - lme);
immutable double hla = atan(slat * hra.radians.tan).degrees;
writefln("HR=%3d; HRA=%7.3f; HLA=%7.3f", h, hra, hla);
}
}
```
Example run:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA=-89.500; HLA= 84.225
HR= -5; HRA=-74.500; HLA= 17.283
HR= -4; HRA=-59.500; HLA=  8.334
HR= -3; HRA=-44.500; HLA=  4.847
HR= -2; HRA=-29.500; HLA=  2.795
HR= -1; HRA=-14.500; HLA=  1.278
HR=  0; HRA=  0.500; HLA= -0.043
HR=  1; HRA= 15.500; HLA= -1.371
HR=  2; HRA= 30.500; HLA= -2.910
HR=  3; HRA= 45.500; HLA= -5.018
HR=  4; HRA= 60.500; HLA= -8.671
HR=  5; HRA= 75.500; HLA=-18.451
HR=  6; HRA= 90.500; HLA= 84.225
```

See #Pascal

## DWScript

Translation of: Java
```procedure PrintSundial(lat, lng, lme : Float);
begin
PrintLn(Format('latitude:        %7.2f', [lat]));
PrintLn(Format('longitude:       %7.2f', [lng]));
PrintLn(Format('legal meridian:  %7.2f', [lme]));

PrintLn(Format('sine of latitude: %.3f', [slat]));
PrintLn(Format('diff longitude:   %.3f', [lng-lme]));
PrintLn('');
PrintLn('Hour, sun hour angle, dial hour line angle from 6am to 6pm');

var h : Integer;
for h:=-6 to 6 do begin
var hra := 15 * h - (lng - lme);
PrintLn(Format('HR=%3d; HRA=%7.3f; HLA=%7.3f', [h, hra, hla]));
end
end;

PrintSundial(-4.95, -150.5, -150);
```
Output:
```latitude:          -4.95
longitude:       -150.50
legal meridian:  -150.00
sine of latitude: -0.086
diff longitude:   -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA=-89.500; HLA= 84.225
HR= -5; HRA=-74.500; HLA= 17.283
HR= -4; HRA=-59.500; HLA=  8.334
HR= -3; HRA=-44.500; HLA=  4.847
HR= -2; HRA=-29.500; HLA=  2.795
HR= -1; HRA=-14.500; HLA=  1.278
HR=  0; HRA=  0.500; HLA= -0.043
HR=  1; HRA= 15.500; HLA= -1.371
HR=  2; HRA= 30.500; HLA= -2.910
HR=  3; HRA= 45.500; HLA= -5.018
HR=  4; HRA= 60.500; HLA= -8.671
HR=  5; HRA= 75.500; HLA=-18.451
HR=  6; HRA= 90.500; HLA=-95.775```

## EasyLang

```func getn s\$ .
write s\$
v = number input
print v
return v
.
lat = getn "Enter latitude: "
lng = getn "Enter longitude: "
merid = getn "Enter legal meridian: "
slat = sin lat
diff = lng - merid
print ""
print "    sine of latitude: " & slat
print "    diff longitude: " & diff
print ""
print "Hour\tSun hour angle\tDial hour line angle"
for h = -6 to 6
hra = 15 * h - diff
hla = atan2 (slat * sin hra) cos hra
print h + 12 & "\t" & hra & "\t\t" & hla
.
```

## ERRE

```PROGRAM SUN_DIAL

END FUNCTION

FUNCTION DEG(X)
DEG=X*180/π
END FUNCTION

BEGIN

INPUT("Enter latitude (degrees)      : ",latitude)
INPUT("Enter longitude (degrees)     : ",longitude)
INPUT("Enter legal meridian (degrees): ",meridian)

PRINT
PRINT(" Time    Sun hour angle  Dial hour line angle")
PRINT("---------------------------------------------")

FOR HOUR=6 TO 18 DO
HRA=15*HOUR-LONGITUDE+MERIDIAN-180
IF ABS(HRA)>90 THEN HLA+=180*SGN(HRA*LATITUDE) END IF
WRITE("##.##         ####.###       ####.###";HOUR;HRA;HLA)
END FOR

END PROGRAM```
Output:
```Enter latitude (degrees)      : ? -4.95
Enter longitude (degrees)     : ? -150.5
Enter legal meridian (degrees): ? -150

Time    Sun hour angle  Dial hour line angle
---------------------------------------------
6.00          -89.500         84.225
7.00          -74.500         17.283
8.00          -59.500          8.334
9.00          -44.500          4.847
10.00          -29.500          2.795
11.00          -14.500          1.278
12.00            0.500         -0.043
13.00           15.500         -1.371
14.00           30.500         -2.910
15.00           45.500         -5.018
16.00           60.500         -8.671
17.00           75.500        -18.451
18.00           90.500        -95.775
```

## Euphoria

Works with: OpenEuphoria
```include std/console.e
include std/mathcons.e

atom lat = prompt_number("Enter Latitude: ",{})
atom lng = prompt_number("Enter Longitude: ",{})
atom lm = prompt_number("Enter Legal Meridian: ",{})
puts(1,'\n')

atom ha, hla

function D2R(atom degrees)
return degrees * PI / 180
end function

return radians * 180 / PI
end function

function atan2(atom y, atom x)
return 2*arctan((sqrt(power(x,2)+power(y,2)) - x)/y)
end function

atom s_lat = sin(D2R(lat))

puts(1,"Hour,  Sun Hour Angle, Dial Hour Line Angle\n")

for hour = -6 to 6 do
ha = hour * 15 - lng + lm
atom s = sin(D2R(ha))
atom c = cos(D2R(ha))
hla = R2D(atan2(s_lat*s,c))
printf(1,"%3d\t\t\t%7.3f\t\t\t%7.3f\n",{hour+12,ha,hla})
end for

if getc(0) then end if```
Output:
```Enter Latitude: -4.95
Enter Longitude: -150.5
Enter Legal Meridian: -150

Hour,  Sun Hour Angle, Dial Hour Line Angle
6	-89.500			 84.225
7	-74.500			 17.283
8	-59.500			  8.334
9	-44.500			  4.847
10	-29.500			  2.795
11	-14.500			  1.278
12	  0.500			 -0.043
13	 15.500			 -1.371
14	 30.500			 -2.910
15	 45.500			 -5.018
16	 60.500			 -8.671
17	 75.500			-18.451
18	 90.500			-95.775
```

## F#

Translation of: C#
```// Learn more about F# at http://fsharp.net

open System

let Degrees = Math.PI / 180.0

Console.Write("Enter latitude: ")
let latitude = Console.ReadLine() |> Double.Parse

Console.Write("Enter longitude: ")
let longitude = Console.ReadLine() |> Double.Parse

Console.Write("Enter legal meridian: ")
let meridian = Console.ReadLine() |> Double.Parse

let sineLatitude = Math.Sin(latitude * Degrees)
Console.WriteLine()
Console.WriteLine("Sine of latitude: {0}",sineLatitude)
Console.WriteLine("Difference of Longitudes (given longitude - meridian): {0}",longitude-meridian)
Console.WriteLine()

printfn "Numbers from 6 AM to 6 PM: "
printfn "Hour\t\tSun hour angle\t Dial hour line angle"

for hour in -6..6 do
let clockHour = if hour < 0 then String.Format("{0}AM",Math.Abs(hour)) else String.Format("{0}PM",hour)
let shr = 15.0*(float)hour - (longitude - meridian)
let dhla = Math.Atan(sineLatitude*Math.Tan(shr*Degrees))/Degrees;
Console.WriteLine("{0}\t\t{1}\t\t{2:0.000}",clockHour,shr,dhla)
done

//To keep the console window open, can be omitted with block comment (" (* comment *) ")
Console.WriteLine("Press any key to continue...")
```
Example output:
```Enter latitude: -4.95
Enter longitude: -150.5
Enter legal meridian: -150

Sine of latitude: -0.0862863657979234
Difference of Longitudes (given longitude - meridian): -0.5

Numbers from 6 AM to 6 PM:
Hour            Sun hour angle   Dial hour line angle
6AM             -89.5           84.225
5AM             -74.5           17.283
4AM             -59.5           8.334
3AM             -44.5           4.847
2AM             -29.5           2.795
1AM             -14.5           1.278
0PM             0.5             -0.043
1PM             15.5            -1.371
2PM             30.5            -2.910
3PM             45.5            -5.018
4PM             60.5            -8.671
5PM             75.5            -18.451
6PM             90.5            84.225
Press any key to continue...
```

## Factor

Translation of: Java
```USING: formatting io kernel locals math math.functions math.libm
math.parser math.ranges math.trig sequences ;
IN: rosetta-code.sundial

: get-num ( str -- x ) write flush readln string>number ;

: get-input ( -- lat lng ref )
"Enter latitude: " "Enter longitude: "
"Enter legal meridian: " [ get-num ] tri@ ;

: .diff ( lat lng ref -- )
- [ deg>rad sin ] dip
"sine of latitude: %.3f\ndiff longitude: %.3f\n" printf ;

: line-angle ( lat hra-rad -- hla )
[ deg>rad sin ] [ [ sin * ] [ cos ] bi ] bi* fatan2 rad>deg
;

:: .angles ( lat lng ref -- )
"Hour, sun hour angle, dial hour line angle from 6am to 6pm"
print
-6 6 [a,b] [
:> h 15.0 h * :> hra!
ref hra lng - + hra!
lat hra deg>rad line-angle :> hla
h hra hla
"HR= %3d;  \t  HRA=%7.3f;  \t  HLA= %7.3f\n" printf
] each ;

: sundial-demo ( -- ) get-input nl 3dup .diff nl .angles ;

MAIN: sundial-demo
```
Output:
```Enter latitude: -4.95
Enter longitude: -150.5
Enter legal meridian: -150

sine of latitude: -0.086
diff longitude: -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR=  -6;  	  HRA=-89.500;  	  HLA=  84.225
HR=  -5;  	  HRA=-74.500;  	  HLA=  17.283
HR=  -4;  	  HRA=-59.500;  	  HLA=   8.334
HR=  -3;  	  HRA=-44.500;  	  HLA=   4.847
HR=  -2;  	  HRA=-29.500;  	  HLA=   2.795
HR=  -1;  	  HRA=-14.500;  	  HLA=   1.278
HR=   0;  	  HRA=  0.500;  	  HLA=  -0.043
HR=   1;  	  HRA= 15.500;  	  HLA=  -1.371
HR=   2;  	  HRA= 30.500;  	  HLA=  -2.910
HR=   3;  	  HRA= 45.500;  	  HLA=  -5.018
HR=   4;  	  HRA= 60.500;  	  HLA=  -8.671
HR=   5;  	  HRA= 75.500;  	  HLA= -18.451
HR=   6;  	  HRA= 90.500;  	  HLA= -95.775
```

## Forth

```: faccept ( -- f )
: >radians ( deg -- rad ) 180e f/ pi f* ;
: >degrees ( rad -- deg ) pi f/ 180e f* ;
: sundial
cr ." Enter latitude: "
cr ." Enter longitude: "
faccept
cr ." Enter legal meridian: "
faccept f- fnegate   ( sin[latitude] -longitude )

cr ." Hour : HourAngle , DialAngle"
7 -6 do
cr i 4 .r ." : "
fover fover i 15 * s>d d>f f+
fdup f. ." , "
>radians fsincos fswap frot f* fswap fatan2 >degrees f.
loop fdrop fdrop ;
```

## Fortran

Works with: gfortran

with -fbackslash option

```program SunDial

real    :: lat, slat, lng, ref
real    :: hra, hla
integer :: h

real, parameter :: pi = 3.14159265358979323846

print *, "Enter latitude"
print *, "Enter longitude"
print *, "Enter legal meridian"

print *

slat = sin(dr(lat))
write(*, '(A,1F6.3)') "sine of latitude: ", slat
write(*, '(A,1F6.3)') "diff longitude: ", lng - ref

print *, "Hour, sun hour angle, dial hour line angle from 6am to 6pm"

do h = -6, 6
hra = 15.0*h
hra = hra - lng + ref
hla = rd( atan( slat * tan( dr(hra) ) ) )
write(*, '(" HR= ",I3,";  \t  HRA=",F7.3,";  \t  HLA= ", F7.3)'), h, hra, hla
end do

contains

function dr(angle)
real :: dr
real, intent(in) :: angle
dr = angle*pi/180.0
end function dr

function rd(angle)
real :: rd
real, intent(in) :: angle
rd = angle*180.0/pi
end function rd

end program SunDial
```

## Go

```package main

import (
"fmt"
"math"
"os"
)

func getnum(prompt string) (r float64) {
fmt.Print(prompt)
if _, err := fmt.Scan(&r); err != nil {
fmt.Println(err)
os.Exit(-1)
}
return
}

func main() {
lat := getnum("Enter latitude       => ")
lng := getnum("Enter longitude      => ")
ref := getnum("Enter legal meridian => ")
slat := math.Sin(lat * math.Pi / 180)
diff := lng - ref
fmt.Println("\n    sine of latitude:   ", slat)
fmt.Println("    diff longitude:     ", diff)
fmt.Println("\nHour, sun hour angle, dial hour line angle from 6am to 6pm")
for h := -6.; h <= 6; h++ {
hra := 15*h - diff
s, c := math.Sincos(hra * math.Pi / 180)
hla := math.Atan2(slat*s, c) * 180 / math.Pi
fmt.Printf("%2.0f %8.3f %8.3f\n", h, hra, hla)
}
}
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:    -0.08628636579792338
diff longitude:      -0.5

Hour, sun hour angle, dial hour line angle from 6am to 6pm
-6  -89.500   84.225
-5  -74.500   17.283
-4  -59.500    8.334
-3  -44.500    4.847
-2  -29.500    2.795
-1  -14.500    1.278
0    0.500   -0.043
1   15.500   -1.371
2   30.500   -2.910
3   45.500   -5.018
4   60.500   -8.671
5   75.500  -18.451
6   90.500  -95.775
```

```roundDec :: Int -> Double -> Double
roundDec d = (/ 10.0 ^ d) . fromIntegral . round . (* 10.0 ^ d)

radToDegr = ((180 / pi) *)

degrToRad = ((pi / 180) *)

main = do
let lat = -4.95
long = -150.5
legalMerid = -150
sinOfLat = sin \$ degrToRad lat
diff = legalMerid - long
(putStrLn . unlines)
[ "Latitude         " ++ show lat
, "Longitude        " ++ show long
, "Legal meridian   " ++ show legalMerid
, "Sine of latitude " ++ show (roundDec 6 sinOfLat)
, "Diff longitude   " ++ show (-diff)
, "hour   sun hour angle   dial hour  line angle"
]
mapM_
(\h ->
let sha = diff + 15 * h
dhla = radToDegr . atan . (sinOfLat *) . tan \$ degrToRad sha
in putStrLn \$
take 7 (show h ++ repeat ' ') ++
take 16 (show (roundDec 3 sha) ++ repeat ' ') ++
" " ++ show (roundDec 3 dhla))
[-6,-5 .. 6]
```
Output:
```*Rosetta.HorSunDial> main
Latitude         -4.95
Longitude        -150.5
Legal meridian   -150.0
Sine of latitude -8.6286e-2
Diff longitude   -0.5
hour   sun hour angle   dial hour  line angle
-6.0   -89.5            84.225
-5.0   -74.5            17.283
-4.0   -59.5            8.334
-3.0   -44.5            4.847
-2.0   -29.5            2.795
-1.0   -14.5            1.278
0.0    0.5              -4.3e-2
1.0    15.5             -1.371
2.0    30.5             -2.91
3.0    45.5             -5.018
4.0    60.5             -8.671
5.0    75.5             -18.451
6.0    90.5             84.225```

## Icon and Unicon

```procedure main()
PrintSundial(-4.95, -150.5, -150);
end

procedure PrintSundial(lat, lng, mer )
write("latitude:        ", lat,
"\nlongitude:       ", lng,
"\nlegal meridian:  ", mer)

slat := sin(dtor(lat))

write("sine of latitude: ",slat,
"\ndiff longitude:   ", lng-mer)
write("\nHour, sun hour angle, dial hour line angle from 6am to 6pm")

every h := -6 to 6 do {
hraRad := dtor(hra := 15 * h - (lng - mer))
write("HR=",
right(if h <= 0 then 12+h else h,2),
if h < 0 then "am" else "pm",
" HRA=",hra,", HLA=",hla)
}
end
```
Output:
```latitude:        -4.95
longitude:       -150.5
legal meridian:  -150
sine of latitude: -0.08628636579792337
diff longitude:   -0.5

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= 6am HRA=-89.5, HLA=84.22483260136025
HR= 7am HRA=-74.5, HLA=17.2829335027853
HR= 8am HRA=-59.5, HLA=8.333711921468083
HR= 9am HRA=-44.5, HLA=4.846708924373172
HR=10am HRA=-29.5, HLA=2.794873809318642
HR=11am HRA=-14.5, HLA=1.278352980919063
HR=12pm HRA=0.5, HLA=-0.04314426995813971
HR= 1pm HRA=15.5, HLA=-1.370787843187052
HR= 2pm HRA=30.5, HLA=-2.909643210076617
HR= 3pm HRA=45.5, HLA=-5.018023174356126
HR= 4pm HRA=60.5, HLA=-8.671396957302381
HR= 5pm HRA=75.5, HLA=-18.45099922256532
HR= 6pm HRA=90.5, HLA=-95.77516739863968```

## J

```require 'trig'
atan2=: {:@*.@j. NB. arc tangent of y divided by x

horiz=: verb define
'lat lng ref'=. y
out=. smoutput@,&":
'Latitude         ' out lat
'Longitude        ' out lng
'Legal meridian   ' out ref
'Sine of latitude ' out slat=. sin rfd lat
'Diff longitude   ' out -diff=. ref - lng
lbl=.'hour  ';'sun hour angle  ';'dial hour line angle'
r=.((,. (,. (atan2 *&slat)/@+.@r.&.rfd)) diff + 15&*) i:6
smoutput lbl ,: ('3.0';'7.3';'7.3') 8!:1 r
)
```
Example:
```   horiz _4.95 _150.5 _150
Latitude         _4.95
Longitude        _150.5
Legal meridian   _150
Sine of latitude _0.0862864
Diff longitude   _0.5
┌──────┬────────────────┬────────────────────┐
│hour  │sun hour angle  │dial hour line angle│
├──────┼────────────────┼────────────────────┤
│ -6   │-89.500         │ 84.225             │
│ -5   │-74.500         │ 17.283             │
│ -4   │-59.500         │  8.334             │
│ -3   │-44.500         │  4.847             │
│ -2   │-29.500         │  2.795             │
│ -1   │-14.500         │  1.278             │
│  0   │  0.500         │ -0.043             │
│  1   │ 15.500         │ -1.371             │
│  2   │ 30.500         │ -2.910             │
│  3   │ 45.500         │ -5.018             │
│  4   │ 60.500         │ -8.671             │
│  5   │ 75.500         │-18.451             │
│  6   │ 90.500         │-95.775             │
└──────┴────────────────┴────────────────────┘
```

## Java

Translation of: C

(Substitutes in atan2 for the hour line angle calculation)

```import java.util.Scanner;

public class Sundial {
public static void main(String[] args) {
double lat, slat, lng, ref;
Scanner sc = new Scanner(System.in);

System.out.print("Enter latitude: ");
lat = sc.nextDouble();
System.out.print("Enter longitude: ");
lng = sc.nextDouble();
System.out.print("Enter legal meridian: ");
ref = sc.nextDouble();
System.out.println();

System.out.printf("sine of latitude: %.3f\n", slat);
System.out.printf("diff longitude: %.3f\n\n", lng - ref);

System.out.printf("Hour, sun hour angle, dial hour line angle from 6am to 6pm\n");

for (int h = -6; h <= 6; h++) {
hra = 15.0 * h;
hra = hra - lng + ref;
System.out.printf("HR= %3d;  \t  HRA=%7.3f;  \t  HLA= %7.3f\n",
h, hra, hla);
}
}
}
```
Output:
```Enter latitude: -4.95
Enter longitude: -150.5
Enter legal meridian: -150

sine of latitude: -0.086
diff longitude: -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR=  -6;  	  HRA=-89.500;  	  HLA=  84.225
HR=  -5;  	  HRA=-74.500;  	  HLA=  17.283
HR=  -4;  	  HRA=-59.500;  	  HLA=   8.334
HR=  -3;  	  HRA=-44.500;  	  HLA=   4.847
HR=  -2;  	  HRA=-29.500;  	  HLA=   2.795
HR=  -1;  	  HRA=-14.500;  	  HLA=   1.278
HR=   0;  	  HRA=  0.500;  	  HLA=  -0.043
HR=   1;  	  HRA= 15.500;  	  HLA=  -1.371
HR=   2;  	  HRA= 30.500;  	  HLA=  -2.910
HR=   3;  	  HRA= 45.500;  	  HLA=  -5.018
HR=   4;  	  HRA= 60.500;  	  HLA=  -8.671
HR=   5;  	  HRA= 75.500;  	  HLA= -18.451
HR=   6;  	  HRA= 90.500;  	  HLA= -95.775```

## jq

Works with: jq

Also works with gojq, the Go implementation of jq.

Generic Utilities

```# `prompts` should be an array defining the prompts, variable names, and their types,
# as exemplified below.
# After all values have been gathered, `get` emits an object defining the bindings.
def get(\$prompts):
label \$out
| foreach range(0;infinite) as \$_ ({i:null, imax: (\$prompts|length)};
if .i == null then .i = 0
elif .i == .imax then break \$out
else .help = null
| first(inputs) as \$n
| \$prompts[.i].type as \$type
| if \$type == null or \$type == "string"
then .result[\$prompts[.i].key] = \$n
| .i += 1
elif \$type == "number"
then (try (\$n|tonumber) catch null) as \$n
| if \$n then .result[\$prompts[.i].key] = \$n
| .i += 1
else .help = .i
end
elif \$type == "integer"
then if (\$n|test("^[0-9]+\$"))
then .result[\$prompts[.i].key] = (\$n|tonumber)
| .i += 1
else .help = .i
end
elif \$type|type == "object"
then if \$type.regex and (\$n | test(\$type.regex))
then .result[\$prompts[.i].key] = \$n
| .i += 1
else .help = .i
end
else .
end
end;
(select(.help) | \$prompts[.help].help // empty),
if .i < .imax then \$prompts[.i].prompt
else .result
end )
;

def lpad(\$len): tostring | (\$len - length) as \$l | (" " * \$l)[:\$l] + .;
def rpad(\$len): tostring | (\$len - length) as \$l | . + ("0" * \$l)[:\$l];

# Input: a string of digits with up to one "."
# Output: the corresponding string representation with exactly \$n decimal digits
def align_decimal(\$n):
tostring
| if index(".")
then capture("(?<i>[0-9]*[.])(?<j>[0-9]{0," + (\$n|tostring) + "})")
else . + "." + ("0" * \$n)
end ;

def pi: 4*(1|atan);```

```def prompts: [
{ prompt: "Enter latitude: ",       key: "lat", type: "number", help: "in degrees"},
{ prompt: "Enter longitude: ",      key: "lng", type: "number", help: "in degrees"},
{ prompt: "Enter legal meridian: ", key: "ref", type: "number", help: "in degrees"}
];

get(prompts)
| if type != "object" then .  # the prompts
else
((.lat * pi / 180)|sin) as \$slat
| (.lng - .ref) as \$diff
| "\n    sine of latitude : \(\$slat)",
"    diff longitude   : \(\$diff)",
"\nHour, sun hour angle, dial hour line angle from 6am to 6pm",
(range(-6;7)  as \$h
| (15*\$h - \$diff) as \$hra
| ((\$hra * pi /180)|sin) as \$s
| ((\$hra * pi /180)|cos) as \$c
| (atan2(\$slat*\$s; \$c) * 180 / pi) as \$hla
end;

Invocation: The program handles user input errors provided the -R option is specified:

```jq -nRr -f horizontal-sundial-calculations.jq
```

Transcript

```Enter latitude:
-4.95
Enter longitude:
-150.5
Enter legal meridian:
?
in degrees
Enter legal meridian:
-150

sine of latitude : -0.08628636579792338
diff longitude   : -0.5

Hour, sun hour angle, dial hour line angle from 6am to 6pm
-6  89.500  84.224
-5  74.500  17.282
-4  59.500   8.333
-3  44.500   4.846
-2  29.500   2.794
-1  14.500   1.278
0   0.500   0.043
1  15.500   1.370
2  30.500   2.909
3  45.500   5.018
4  60.500   8.671
5  75.500  18.450
6  90.500  95.775
```

## Julia

Translation of: Python
```print("Enter latitude       => ")
print("Enter longitude      => ")
print("Enter legal meridian => ")
println()

@printf "    sine of latitude:   %.3f\n" slat
@printf "    diff longitude:     %.3f\n" (lng - ref)

println("\nHour, sun hour angle, dial hour line angle from 6am to 6pm\n")

for h in -6:6
hra = 15 * h
hra -= lng - ref
@printf "HR = %3d; HRA = %7.3f; HLA = %7.3f\n" h hra hla
end
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm

HR =  -6; HRA = -89.500; HLA =  84.225
HR =  -5; HRA = -74.500; HLA =  17.283
HR =  -4; HRA = -59.500; HLA =   8.334
HR =  -3; HRA = -44.500; HLA =   4.847
HR =  -2; HRA = -29.500; HLA =   2.795
HR =  -1; HRA = -14.500; HLA =   1.278
HR =   0; HRA =   0.500; HLA =  -0.043
HR =   1; HRA =  15.500; HLA =  -1.371
HR =   2; HRA =  30.500; HLA =  -2.910
HR =   3; HRA =  45.500; HLA =  -5.018
HR =   4; HRA =  60.500; HLA =  -8.671
HR =   5; HRA =  75.500; HLA = -18.451
HR =   6; HRA =  90.500; HLA =  84.225
```

## Kotlin

```import java.lang.Math.atan2
import java.lang.Math.cos
import java.lang.Math.sin
import java.lang.Math.toDegrees

// version 1.1.4

fun main(args: Array<String>) {
println("Please enter the following in degrees:")
print("  Latitude       : ")
print("  Longitude      : ")
print("  Legal Meridian : ")

val diff = lng - mer
println("\nSine of latitude     = \${"%.6f".format(slat)}")
println("Longitude - Meridian = \${"%.3f".format(diff)}\n")
println("Hour   Sun Hour Angle  Dial Hour Line Angle")
println("-----  --------------  --------------------")
println("              °               °")
for (h in -6..6) {
var hr = h + 12
val am = if (hr < 12) "AM" else "PM"
if (hr > 12) hr -= 12
val sha = 15.0 * h - diff
println("%2d %s      %+7.3f         %+7.3f".format(hr, am, sha, dhla))
}
}
```

Sample input/output:

Output:
```Please enter the following in degrees:
Latitude       : -4.95
Longitude      : -150.5
Legal Meridian : -150

Sine of latitude     = -0.086286
Longitude - Meridian = -0.500

Hour   Sun Hour Angle  Dial Hour Line Angle
-----  --------------  --------------------
°               °
6 AM      -89.500         +84.225
7 AM      -74.500         +17.283
8 AM      -59.500          +8.334
9 AM      -44.500          +4.847
10 AM      -29.500          +2.795
11 AM      -14.500          +1.278
12 PM       +0.500          -0.043
1 PM      +15.500          -1.371
2 PM      +30.500          -2.910
3 PM      +45.500          -5.018
4 PM      +60.500          -8.671
5 PM      +75.500         -18.451
6 PM      +90.500         -95.775
```

## LiveCode

Translation of BASIC versions.

```on mouseUp
if it is empty then exit mouseup
// -150.5, -4.95, -150.0
put item 1 of it into longitude
put item 2 of it into latitude
put item 3 of it into meridian

repeat with hour = 6 TO 18
put 15 *hour - longitude + meridian - 180 into hra
if abs(hra) > 90 then put hla + 180 * sgn(hra *latitude) into hla
put hour && hra && hla & cr after sunhours
end repeat
put sunhours
end mouseUp

return theta * (180 / pi)

return theta * (pi / 180)

function sgn x
if x >0 then return 1 else return -1
end sgn```

## Logo

```type "|Enter latitude: |
type "|Enter longitude: |
type "|Enter legal meridian: |

print [Hour : HourAngle , DialAngle]
for [hour -6 6] [
make "hra 15 * :hour - :long
make "hla arctan product sin :lat quotient sin :hra cos :hra
print (sentence "hour :hour ": :hra ", :hla)
]```

## Lua

Translation of: Python
```io.write("Enter latitude       => ")

io.write("Enter longitude      => ")

io.write("Enter legal meridian => ")

print()

print(string.format("    sine of latitude:   %.3f", slat))
print(string.format("    diff longitude:     %.3f", lng-ref))
print()
print("Hour, sun hour angle, dial hour line angle from 6am to 6pm")

for h = -6, 6 do
hra = 15 * h
hra = hra - (lng - ref)
print(string.format("HR=%3d; HRA=%7.3f; HLA=%7.3f", h, hra, hla))
end
```

## Mathematica / Wolfram Language

```lat = Input["latitude", -4.95];
lng = Input["longitude", -150.5];
ref = Input["legal meridian", -150];

slat = Sin[lat Degree];
Table[
hra = 15 h;
hra -= lng - ref;
hla = N@ArcTan[slat Tan[hra Degree]]/Degree;
{h, hra, hla}
,
{h, -6, 6}
] // Prepend[{"Hour", "Sun hour angle",
"Dial hour line angle"}] // Grid
```
Output:
```Hour   Sun hour angle   Dial hour line angle
-6     -89.5            84.2248
-5     -74.5            17.2829
-4     -59.5            8.33371
-3     -44.5            4.84671
-2     -29.5            2.79487
-1     -14.5            1.27835
0      0.5              -0.0431443
1      15.5             -1.37079
2      30.5             -2.90964
3      45.5             -5.01802
4      60.5             -8.6714
5      75.5             -18.451
6      90.5             84.2248```

## МК-61/52

```МГ	П2	->	МГ	П1	->	МГ	sin	П0
6	/-/	П3
ИП3	1	5	*	ИП1	ИП2	-	-	П4
tg	ИП0	*	arctg	ИП4	ИП3	С/П
ИП3	1	+	П3	7	-	x=0	12
Сx	С/П
```

Input: latitude ^ longitude ^ legal meridian С/П ... С/П ...; switch of the angle measure set to Г.

Example: -4,57 ^ -150,3 ^ -150 С/П.

Output: hour in РX, sun hour angle in РY, dial hour line angle in РZ.

## Modula-2

Translation of: ALGOL-68
Works with: ADW Modula-2 version any (Compile with the linker option Console Application).
```MODULE SunDial;

FROM STextIO IMPORT
WriteString, WriteLn, SkipLine;
FROM SRealIO IMPORT
FROM SWholeIO IMPORT
WriteInt;
FROM RealMath IMPORT
sin, pi, arctan, tan;

VAR
Lat, Slat, Lng, Ref: REAL;
Hour: INTEGER;
HourAngle, HourLineAngle: REAL;
BEGIN
WriteString("Enter latitude       => ");
SkipLine;
WriteString("Enter longitude      => ");
SkipLine;
WriteString("Enter legal meridian => ");
SkipLine;
WriteLn;
Slat := sin(Lat * pi / 180.0);
WriteString("    sine of latitude:   ");
WriteFloat(Slat, 2, 8);
WriteLn;
WriteString("    diff longitude:     ");
WriteFixed(Lng - Ref, 3, 1);
WriteLn;
WriteLn;
WriteString("Hour, sun hour angle, dial hour line angle from 6am to 6pm");
WriteLn;
FOR Hour := -6 TO 6 DO
HourAngle := FLOAT(15 * Hour);
HourAngle := HourAngle - (Lng - Ref); (* correct for longitude difference *)
HourLineAngle := arctan(Slat * tan(HourAngle * pi / 180.0)) * 180.0 / pi;
WriteString("HR=");
WriteInt(Hour, 3);
WriteString("; HRA=");
WriteFixed(HourAngle, 3, 8);
WriteString("; HLA=");
WriteFixed(HourLineAngle, 3, 8);
WriteLn;
END;
END SunDial.
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -8.6E-02
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.500; HLA=  84.225
HR= -5; HRA= -74.500; HLA=  17.283
HR= -4; HRA= -59.500; HLA=   8.334
HR= -3; HRA= -44.500; HLA=   4.847
HR= -2; HRA= -29.500; HLA=   2.795
HR= -1; HRA= -14.500; HLA=   1.278
HR=  0; HRA=   0.500; HLA=  -0.043
HR=  1; HRA=  15.500; HLA=  -1.371
HR=  2; HRA=  30.500; HLA=  -2.910
HR=  3; HRA=  45.500; HLA=  -5.018
HR=  4; HRA=  60.500; HLA=  -8.671
HR=  5; HRA=  75.500; HLA= -18.451
HR=  6; HRA=  90.500; HLA=  84.225
```

## newLISP

Translation of: Lua
```(define pi 3.141592654)
(define (radians degrees) (mul degrees (div pi 180)))

(print "Enter latitude       => ")

(print "Enter longitude      => ")

(print "Enter legal meridian => ")

(println)

(println (format "    sine of latitude:   %.3f" slat))
(println (format "    diff longitude:     %.3f" (sub lng rf)))
(println)
(println "Hour, sun hour angle, dial hour line angle from 6am to 6pm")

(for (h -6 6)
(set 'hra (sub (mul 15 h) lng rf))
(set 'hla (degrees (atan (mul slat (tan (radians hra))))))
(println (format "HR=%3d; HRA=%7.3f; HLA=%7.3f" h hra hla))
)

(exit)
```

## Nim

Translation of: Python
```import rdstdin, strutils, math, strformat

let lat = parseFloat readLineFromStdin "Enter latitude       => "
let lng = parseFloat readLineFromStdin "Enter longitude      => "
let med = parseFloat readLineFromStdin "Enter legal meridian => "
echo ""

echo &"    sine of latitude:   {slat:.3f}"
echo &"    diff longitude:     {lng-med:.3f}"
echo ""
echo "Hour, sun hour angle, dial hour line angle from 6am to 6pm"

for h in -6..6:
let hra = float(15 * h) - lng + med
echo &"HR={h:3d}; HRA={hra:7.3f}; HLA={hla:7.3f}"
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA=-89.500; HLA= 84.225
HR= -5; HRA=-74.500; HLA= 17.283
HR= -4; HRA=-59.500; HLA=  8.334
HR= -3; HRA=-44.500; HLA=  4.847
HR= -2; HRA=-29.500; HLA=  2.795
HR= -1; HRA=-14.500; HLA=  1.278
HR=  0; HRA=  0.500; HLA= -0.043
HR=  1; HRA= 15.500; HLA= -1.371
HR=  2; HRA= 30.500; HLA= -2.910
HR=  3; HRA= 45.500; HLA= -5.018
HR=  4; HRA= 60.500; HLA= -8.671
HR=  5; HRA= 75.500; HLA=-18.451
HR=  6; HRA= 90.500; HLA= 84.225```

## Objeck

Translation of: C#
```class Sundial {
function : Main(args : String[]) ~ Nil {
"Enter latitude: "->Print();
"Enter longitude: "->Print();
"Enter legal meridian: "->Print();
'\n'->PrintLine();

"sine of latitude: {\$slat}"->PrintLine();
value := lng - ref;
"diff longitude: {\$value}"->PrintLine();
'\n'->PrintLine();

"Hour\t\tsun hour angle\t\tdial hour line angle from 6am to 6pm"->PrintLine();
for (h := -6; h <= 6; h+=1;) {
hra := 15.0 * h;
hra -= lng - ref;
hla := (slat* (hra*2*Float->Pi()/360.0)->Tan())->ArcTan() * 360.0 / (2*Float->Pi());
"HR={\$h}\t\tHRA={\$hra}\t\tHLA={\$hla}"->PrintLine();
};
}
}```

## OCaml

Translation of: ALGOL 68
```let () =
let pi = 4. *. atan 1. in
print_endline "Enter latitude		=> ";
let lat = read_float () in
print_endline "Enter longitude	=> ";
let lng = read_float () in
print_endline "Enter legal meridian	=> ";
let ref = read_float () in
print_newline ();

let slat = sin (lat *. 2. *. pi /. 360.) in
Printf.printf "    sine of latitude:   %.3f\n" slat;
Printf.printf "    diff longitude:     %.3f\n" (lng -. ref);
print_newline ();

print_endline "Hour, sun hour angle, dial hour line angle from 6am to 6pm";

for h = -6 to 6 do
let hra = 15. *. float h in
let hra = hra -. (lng -. ref) in
let hla = atan (slat *. tan (hra *. 2. *. pi /. 360.)) *. 360. /. (2. *. pi) in
Printf.printf "HR= %3d;  \t  HRA=%7.3f;  \t  HLA= %7.3f\n" h hra hla;
done
```
Output:
```Enter latitude		=>
-4.95
Enter longitude	=>
-150.5
Enter legal meridian	=>
-150.

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR=  -6;  	  HRA=-89.500;  	  HLA=  84.225
HR=  -5;  	  HRA=-74.500;  	  HLA=  17.283
HR=  -4;  	  HRA=-59.500;  	  HLA=   8.334
HR=  -3;  	  HRA=-44.500;  	  HLA=   4.847
HR=  -2;  	  HRA=-29.500;  	  HLA=   2.795
HR=  -1;  	  HRA=-14.500;  	  HLA=   1.278
HR=   0;  	  HRA=  0.500;  	  HLA=  -0.043
HR=   1;  	  HRA= 15.500;  	  HLA=  -1.371
HR=   2;  	  HRA= 30.500;  	  HLA=  -2.910
HR=   3;  	  HRA= 45.500;  	  HLA=  -5.018
HR=   4;  	  HRA= 60.500;  	  HLA=  -8.671
HR=   5;  	  HRA= 75.500;  	  HLA= -18.451
HR=   6;  	  HRA= 90.500;  	  HLA=  84.225
```

## Octave

```lat = input("Enter latitude: ");
lng = input("Enter longitude: ");
ref = input("Enter legal meridian: ");
slat = sind(lat);
printf("sine of latitude: %.3f\n", slat);
printf("diff longitude: %.3f\n\n", lng - ref);
printf("Hour, sun hour angle, dial hour line angle from 6am to 6pm\n");

hras = [-6:6] .* 15.0 .- lng .+ ref;
hlas = atand( tand(hras) .* slat );
printf("HR= %3d;  \t  HRA=%7.3f;  \t  HLA= %7.3f\n",
[ [-6:6]; hras; hlas] );
```

## OoRexx

Translation of: REXX
```/*REXX pgm shows:  hour,  sun hour angle,  dial hour line angle,  6am ---> 6pm*/
/* Use trigonometric functions provided by rxCalc                             */
parse arg lat lng mer .               /*get the optional arguments from the CL*/
/*None specified?   Then use the default of Jules   */
/*Verne's Lincoln Island,  aka  Ernest Legouve Reef.*/

if lat=='' | lat==',' then lat=-4.95  /*Not specified?   Then use the default.*/
if lng=='' | lng==',' then lng=-150.5 /* "      "          "   "   "     "    */
if mer=='' | mer==',' then mer=-150   /* "      "          "   "   "     "    */
L=max(length(lat), length(lng), length(mer))
say '       latitude:' right(lat,L)
say '      longitude:' right(lng,L)
say ' legal meridian:' right(mer,L)
sineLat=rxCalcSin(lat,,'D')
w1=max(length('hour')     ,length('midnight'))+2
w2=max(length('sun hour') ,length('angle'))+2
w3=max(length('dial hour'),length('line angle'))+2
indent=left('',30)               /*make the presentation prettier.      */
say indent center('    ',w1) center('sun hour',w2) center('dial hour' ,w3)
say indent center('hour',w1) center('angle'   ,w2) center('line angle',w3)
call sep                         /*add a separator line for the eyeballs*/

do h=-6  to 6                    /*Okey dokey then, let's get busy.     */
select
when abs(h)==12  then hc='midnight'      /*above the arctic circle? */
when h<0  then hc=-h 'am'    /*convert the hour for human beans.    */
when h==0 then hc='noon'     /*  ... easier to understand now.      */
when h>0  then hc=h 'pm'     /*  ... even more meaningful.          */
end   /*select*/
hra=15*h-lng+mer
hla=rxCalcArctan(sineLat*rxCalctan(hra,,'D'),,'D')
say indent center(hc,w1) right(format(hra,,1),w2) right(format(hla,,1),w3)
end
call sep
Exit
sep: say indent copies('-',w1) copies('-',w2) copies('-',w3)
Return
::Requires rxMath Library```
Output:

Not the same as for REXX anymore as the REXX computer programming example has been updated.

## Pascal

```Program SunDial;

Const
pi  = 3.14159265358979323846;
dr  = pi/180.0;
rd  = 180.0/pi;
tab =  chr(9);

Var
lat, slat, lng, ref : Real;
hla, hra	       : Real;
h		       : Integer;

function tan(val : Real) : Real;
begin
tan := sin(val)/cos(val)
end;

Begin
WriteLn;
slat := sin(lat * dr);
WriteLn('sine of latitude: ', slat);
WriteLn('diff longitude: ', lng - ref);
WriteLn('Hour, sun hour angle, dial hour line angle from 6am to 6pm');
for h := -6 to 6 do begin
hra := 15.0 * h;
hra := hra - lng + ref;
hla := arctan(slat * tan(hra * dr)) * rd;
WriteLn('HR= ', h:3, ';  ',
tab, '  HRA= ', hra:7:3, ';  ',
tab, '  HLA= ', hla:7:3)
end
end.
```

## Perl

Translation of: Raku
```use utf8;
binmode STDOUT, ":utf8";

use constant π => 3.14159265;

sub d2r { \$_[0] * π / 180 } # degrees to radians
sub r2d { \$_[0] * 180 / π } # radians to degrees

print 'Enter latitude       => '; \$latitude  = <>;
print 'Enter longitude      => '; \$longitude = <>;
print 'Enter legal meridian => '; \$meridian  = <>;

\$lat_sin = sin( d2r(\$latitude) );
\$offset = \$meridian - \$longitude;
print 'Sine of latitude: ' . sprintf "%.4f\n", \$lat_sin;
print 'Longitude offset: ' . \$offset . "\n";
print '=' x 48 . "\n";
print " Hour : Sun hour angle°: Dial hour line angle°\n";

for \$hour (-6 .. 6) {
my \$sun_deg  = \$hour * 15 + \$offset;
my \$line_deg = r2d atan2( ( sin(d2r(\$sun_deg)) * \$lat_sin ), cos(d2r(\$sun_deg)) );
printf "%2d %s     %8.3f            %8.3f\n",
(\$hour + 12) % 12 || 12, (\$hour < 0 ? 'AM' : 'PM'), \$sun_deg, \$line_deg;
}
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

Sine of latitude: -0.0863
Longitude offset: 0.5
================================================
Hour : Sun hour angle°: Dial hour line angle°
6 AM      -89.500              84.225
7 AM      -74.500              17.283
8 AM      -59.500               8.334
9 AM      -44.500               4.847
10 AM      -29.500               2.795
11 AM      -14.500               1.278
12 PM        0.500              -0.043
1 PM       15.500              -1.371
2 PM       30.500              -2.910
3 PM       45.500              -5.018
4 PM       60.500              -8.671
5 PM       75.500             -18.451
6 PM       90.500             -95.775```

## Phix

For better behaviour/proper input on pwa/p2js I suppose this should really be a pGUI app.

```with javascript_semantics
function prompt(string text, atom v)
if platform()!=JS then
printf(1,"Enter %s (%g):",{text,v})
puts(1, '\n')
end if
else
printf(1,"%s:%g\n",{text,v})
end if
return v
end function

atom lat = prompt("Latitude",-4.95),
lng = prompt("Longitude",-150.5),
mer = prompt("Legal Meridian",-150),

printf(1,"""

Sine of latitude: %g
Longitude offset: %g

Hour    Sun hour angle  Dial hour line angle
--------  --------------  --------------------
""",{slat,lng-mer})

for hour = -6 to 6 do
atom ha = hour * 15 - lng + mer,
integer hour12 = iff(hour<=0?hour+12:hour)
string am = iff(hour<0?"am":"pm")
printf(1,"%3d:00%s %12.3f %17.3f\n",{hour12,am,ha,hla})
end for
```
Output:
```Enter Latitude (-4.95):
Enter Longitude (-150.5):
Enter Legal Meridian (-150):

Sine of latitude: -0.086286
Longitude offset: -0.5

Hour    Sun hour angle  Dial hour line angle
--------  --------------  --------------------
6:00am      -89.500            84.225
7:00am      -74.500            17.283
8:00am      -59.500             8.334
9:00am      -44.500             4.847
10:00am      -29.500             2.795
11:00am      -14.500             1.278
12:00pm        0.500            -0.043
1:00pm       15.500            -1.371
2:00pm       30.500            -2.910
3:00pm       45.500            -5.018
4:00pm       60.500            -8.671
5:00pm       75.500           -18.451
6:00pm       90.500           -95.775
```

## PicoLisp

Translation of: ALGOL 68
```(load "@lib/math.l")

(de prompt (Str . Arg)
(prin Str " => ")
(set (car Arg) (in NIL (read))) )

(use (Lat Lng Ref)
(prompt "Enter latitude      " Lat)
(prompt "Enter longitude     " Lng)
(prompt "Enter legal meridian" Ref)
(prinl)
(let Slat (sin (*/ Lat pi 180.0))
(prinl "    sine of latitude:   " (round Slat))
(prinl "    diff longitude:     " (round (- Lng Ref)))
(prinl)
(prinl "Hour, sun hour angle, dial hour line angle from 6am to 6pm")
(for H (range -6 6)
(let Hra (- (* 15.0 H) (- Lng Ref))
(let Hla (*/ (atan (*/ Slat (tan (*/ Hra pi 180.0)) 1.0)) 180.0 pi)
(prinl
"HR="
(align 3 H)
"; HRA="
(align 8 (round Hra))
"; HLA="
(align 8 (round Hla)) ) ) ) ) ) )```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150.          # Don't omit the '.' here

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.500; HLA=  84.225
HR= -5; HRA= -74.500; HLA=  17.283
HR= -4; HRA= -59.500; HLA=   8.334
HR= -3; HRA= -44.500; HLA=   4.847
HR= -2; HRA= -29.500; HLA=   2.795
HR= -1; HRA= -14.500; HLA=   1.278
HR=  0; HRA=   0.500; HLA=  -0.043
HR=  1; HRA=  15.500; HLA=  -1.371
HR=  2; HRA=  30.500; HLA=  -2.910
HR=  3; HRA=  45.500; HLA=  -5.018
HR=  4; HRA=  60.500; HLA=  -8.671
HR=  5; HRA=  75.500; HLA= -18.451
HR=  6; HRA=  90.500; HLA=  84.225```

## PowerShell

```function Get-Sundial
{
[CmdletBinding()]
[OutputType([PSCustomObject])]
Param
(
[Parameter(Mandatory=\$true)]
[ValidateRange(-90,90)]
[double]
\$Latitude,

[Parameter(Mandatory=\$true)]
[ValidateRange(-180,180)]
[double]
\$Longitude,

[Parameter(Mandatory=\$true)]
[ValidateRange(-180,180)]
[double]
\$Meridian
)

[double]\$sinLat = [Math]::Sin(\$Latitude*2*[Math]::PI/360)

\$object = [PSCustomObject]@{
"Sine of Latitude"     = [Math]::Round(\$sinLat,3)
"Longitude Difference" = \$Longitude - \$Meridian
}

[int[]]\$hours = -6..6

\$hoursArray = foreach (\$hour in \$hours)
{
[double]\$hra = (15 * \$hour) - (\$Longitude - \$Meridian)
[double]\$hla = [Math]::Atan(\$sinLat*[Math]::Tan(\$hra*2*[Math]::PI/360))*360/(2*[Math]::PI)
[PSCustomObject]@{
"Hour"                 = "{0,8}" -f ((Get-Date -Hour (\$hour + 12) -Minute 0).ToString("t"))
"Sun Hour Angle"       = [Math]::Round(\$hra,3)
"Dial Hour Line Angle" = [Math]::Round(\$hla,3)
}
}

\$object | Add-Member -MemberType NoteProperty -Name Hours -Value \$hoursArray -PassThru
}

\$sundial = Get-Sundial -Latitude -4.95 -Longitude -150.5 -Meridian -150
\$sundial | Select-Object -Property "Sine of Latitude", "Longitude Difference" | Format-List
\$sundial.Hours | Format-Table -AutoSize
```
Output:
```
Sine of Latitude     : -0.086
Longitude Difference : -0.5

Hour     Sun Hour Angle Dial Hour Line Angle
----     -------------- --------------------
6:00 AM          -89.5               84.225
7:00 AM          -74.5               17.283
8:00 AM          -59.5                8.334
9:00 AM          -44.5                4.847
10:00 AM          -29.5                2.795
11:00 AM          -14.5                1.278
12:00 PM            0.5               -0.043
1:00 PM           15.5               -1.371
2:00 PM           30.5                -2.91
3:00 PM           45.5               -5.018
4:00 PM           60.5               -8.671
5:00 PM           75.5              -18.451
6:00 PM           90.5               84.225

```

## Python

Translation of: ALGOL 68
```from __future__ import print_function
import math
try: raw_input
except: raw_input = input

lat = float(raw_input("Enter latitude       => "))
lng = float(raw_input("Enter longitude      => "))
ref = float(raw_input("Enter legal meridian => "))
print()

print("    sine of latitude:   %.3f" % slat)
print("    diff longitude:     %.3f" % (lng-ref))
print()
print("Hour, sun hour angle, dial hour line angle from 6am to 6pm")

for h in range(-6, 7):
hra = 15 * h
hra -= lng - ref
print("HR=%3d; HRA=%7.3f; HLA=%7.3f" % (h, hra, hla))
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.086
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA=-89.500; HLA= 84.225
HR= -5; HRA=-74.500; HLA= 17.283
HR= -4; HRA=-59.500; HLA=  8.334
HR= -3; HRA=-44.500; HLA=  4.847
HR= -2; HRA=-29.500; HLA=  2.795
HR= -1; HRA=-14.500; HLA=  1.278
HR=  0; HRA=  0.500; HLA= -0.043
HR=  1; HRA= 15.500; HLA= -1.371
HR=  2; HRA= 30.500; HLA= -2.910
HR=  3; HRA= 45.500; HLA= -5.018
HR=  4; HRA= 60.500; HLA= -8.671
HR=  5; HRA= 75.500; HLA=-18.451
HR=  6; HRA= 90.500; HLA= 84.225
```

## Racket

Translation of: ALGOL 68

I must say, I'm a bit astonished by the fact that no one is bothered by the atan problem (HLA=84.225) that appears in the ALGOL 68 solution and all of the ones derived from it. Composing tan & atan produces the identity only in the range [-90,90], and you have to correct for angles outside of this.

Also, I apologize for the length; I added quite a bit of commenting, and I peeled things out into functions so I could test them. Hopefully, the result--though longer--is also more readable.

```#lang racket

;; print the table for a given latitude and longitude-offset,
;; given in degrees
(define (print-table lat long-offset)
(display
(~a "    sine of latitude: "
(~r (sin (deg->rad lat)) #:precision '(= 3))
"\n"
"    diff longitude:   "
(~r long-offset #:precision '(= 3))
"\n\nHour, sun hour angle, dial hour line angle "
"from 6am to 6pm\n"))
;; print the table
(for ([h (in-range -6 7)])
(define hra (- (* 15 h) long-offset))
(define hla (to-hla lat hra))
(display (~a "HR="(pad-to 3 (~a h))"; "
"HRA="(pad-to 7 (~r hra #:precision '(= 3)))"; "
"HLA="(pad-to 7 (~r hla #:precision '(= 3)))"\n"))))

;; compute the angle on the gnomon corresponding to a
;; given angle of the sun (angles given and returned in degrees)
(define (to-hla lat ang)
(define lat-sign (cond [(< lat 0) -1] [else 1]))
;; move to the right quadrant for
;; angles outside [-90,90]
(define correction (* (cond [(< ang -90) -180]
[(> ang 90) 180]
[else 0])
lat-sign))
correction))

;; write the prompt, return the entered number
(define (prompt->num p)
(printf "~a" p)

(define (deg->rad d) (* 2 pi (/ d 360)))

(define (rad->deg r) (* 360 (/ r (* 2 pi))))

;; add spaces to reach given length
(define spaces-needed (max 0 (- cols (string-length str))))
(string-append
(list->string (for/list ([i spaces-needed]) #\space))
str))

;; INPUT PARAMETERS, PRINT TABLE:
(define lat (prompt->num "Enter latitude       => "))
(define lng (prompt->num "Enter longitude      => "))
(define ref (prompt->num "Enter legal meridian => "))

(print-table lat (- lng ref))

;; test cases for angle conversion
(require rackunit)
(check < (to-hla 30 89) 90)
(check-= (to-hla 30 90) 90 1e-5)
(check > (to-hla 30 91) 90)
(check > (to-hla 30 -89) -90)
(check-= (to-hla 30 90) 90 1e-5)
(check < (to-hla 30 -91) -90)
(check < (to-hla -30 -89) 90)
(check-= (to-hla -30 -90) 90 1e-5)
(check > (to-hla -30 -91) 90)
(check > (to-hla -30 89) -90)
(check-= (to-hla -30 90) -90 1e-5)
(check < (to-hla -30 91) -90)
```
Output:
```Welcome to DrRacket, version 5.3.3.5--2013-02-20(5eddac74/d) [3m].
Language: racket; memory limit: 512 MB.
Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150
sine of latitude: -0.086
diff longitude:   -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA=-89.500; HLA= 84.225
HR= -5; HRA=-74.500; HLA= 17.283
HR= -4; HRA=-59.500; HLA=  8.334
HR= -3; HRA=-44.500; HLA=  4.847
HR= -2; HRA=-29.500; HLA=  2.795
HR= -1; HRA=-14.500; HLA=  1.278
HR=  0; HRA=  0.500; HLA= -0.043
HR=  1; HRA= 15.500; HLA= -1.371
HR=  2; HRA= 30.500; HLA= -2.910
HR=  3; HRA= 45.500; HLA= -5.018
HR=  4; HRA= 60.500; HLA= -8.671
HR=  5; HRA= 75.500; HLA=-18.451
HR=  6; HRA= 90.500; HLA=-95.775
>
```

## Raku

(formerly Perl 6)

```sub postfix:<°> (\$a) { \$a * pi / 180 } # degrees to radians
sub postfix:<®> (\$a) { \$a * 180 / pi } # radians to degrees

my \$latitude  = prompt 'Enter latitude       => ';
my \$longitude = prompt 'Enter longitude      => ';
my \$meridian  = prompt 'Enter legal meridian => ';

my \$lat_sin = sin( \$latitude° );
say 'Sine of latitude: ', \$lat_sin.fmt("%.4f");
say 'Longitude offset: ', my \$offset = \$meridian - \$longitude;
say '=' x 48;
say ' Hour  : Sun hour angle° : Dial hour line angle°';

for -6 .. 6 -> \$hour {
my \$sun_deg  = \$hour * 15 + \$offset;
my \$line_deg = atan2( ( sin(\$sun_deg°) * \$lat_sin ), cos(\$sun_deg°) )®;
printf "%2d %s      %7.3f             %7.3f\n",
(\$hour + 12) % 12 || 12, (\$hour < 0 ?? 'AM' !! 'PM'), \$sun_deg, \$line_deg;
}
```
Example output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150
Sine of latitude: -0.0863
Longitude offset: 0.5
================================================
Hour  : Sun hour angle° : Dial hour line angle°
6 AM      -89.500              84.225
7 AM      -74.500              17.283
8 AM      -59.500               8.334
9 AM      -44.500               4.847
10 AM      -29.500               2.795
11 AM      -14.500               1.278
12 PM        0.500              -0.043
1 PM       15.500              -1.371
2 PM       30.500              -2.910
3 PM       45.500              -5.018
4 PM       60.500              -8.671
5 PM       75.500             -18.451
6 PM       90.500             -95.775
```

## REXX

The REXX language doesn't have the usual trigonometric functions, nor for that matter, a   sqrt   (square root) function,
so these as well as   pi   were added to this program.

The   legal meridian   is calculated instead of relying on a specified amount.

The time range was extended   (to include quarter─hour times),   and to show that the  dial hour line angle  just doesn't
change its sign when it exceeds  ± 90º.

No attempt was made to explain the inner workings of the trigonometric functions.

```/*REXX program displays:   hour,  sun hour angle,  dial hour line angle,  6am ───► 6pm. */
numeric digits length( pi() )    -    length(.)  /*in case sundial is in polar regions. */
parse arg lat lng .                              /*obtain optional arguments from the CL*/
/*     ┌───────────◄ None specified?  Then use the default*/
/*     │             of Jules Verne's Lincoln Island,     */
\$= left('', 30)               /*     ↓             aka      Ernest Legouve Reef.        */
if lat=='' | lat==","  then lat=   -4.95         /*Not specified?  Then use the default.*/
if lng=='' | lng==","  then lng= -150.5          /* "      "         "   "   "     "    */
mer= format(lng/15, , 0)  *  15                  /*calculate legal meridian longitude.  */
sineLat= sin( d2r(lat) )                         /*calculate sine of (radian) latitude. */
w1= max( length('hour'     ), length("midnight"  ))  + 2   /*compute the max hour  width*/
w2= max( length('sun hour' ), length("angle"     ))  + 2   /*   "     "   " angle    "  */
w3= max( length('dial hour'), length("line angle"))  + 2   /*   "     "   " lineº    "  */
L=  max( length(lat), length(lng), length(mer) ) /*find the maximum length of 3 numbers.*/
say '       latitude:'    right(lat, L)     /*display the  latitude to the terminal*/
say '      longitude:'    right(lng, L)     /*   "     "  longitude  "  "     "    */
say ' legal meridian:'    right(mer, L)     /*   "    legal meridian "  "     "    */
say \$  center('    ', w1)    center("sun hour", w2)      center('dial hour' , w3)
say \$  center('hour', w1)    center(" angle"  , w2)      center('line angle', w3)
call sep                                         /*to help a one─eyed pirate's eyeball. */
do h=5  to 19  by .25                    /*Okey dokey then, now let's show stuff*/
hra= 15 * h   -   lng  +  mer - 180      /*calculate sun hour angle (in degrees)*/
hla= r2d( Atan(sineLat * tan(d2r(hra)))) /*this is the heavy lifting calculation*/
if abs(hra)>90  then hla= hla + 180 * sign(hra*lat)  /*adjust for negative angle*/
call civil                               /*convert the time─of─day to civil time*/
say \$ center(hc, w1)   right(format(hra,,1), w2-2)@   right(format(hla,,1), w3-5)
end        /*h*/
call sep                                         /*to help a one─eyed pirate's eyeball. */
exit 0                                           /*stick a fork in it,  we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
pi:   pi= 3.1415926535897932384626433832795028841971693993751058209749445923078; return pi
d2d:  return arg(1)              // 360          /*normalize degrees ──► a unit circle. */
d2r:  return r2r( arg(1) * pi()   / 180)         /*convert degrees   ──► radians.       */
r2d:  return d2d( (arg(1) * 180   / pi() )  )    /*convert radians   ──► degrees.       */
r2r:  return arg(1)              //(pi() * 2)    /*normalize radians ──► a unit circle. */
sep:  say \$  copies('═', w1)  copies("═", w2)   copies('═', w3);   @= left('',3);   return
tan:  procedure; parse arg x;  _= cos(x);   if _=0  then call tanErr;      return sin(x)/_
tellErr: say;    say '*** error ***';       say;        say arg(1);      say;      exit 13
AsinErr: call tellErr 'Asin(x),  X  must be in the range of  -1 ──► +1,  X='   x
AcosErr: call tellErr 'Acos(x),  X  must be in the range of  -1 ──► +1,  X='   x
tanErr:  call tellErr 'tan(' || x") causes division by zero,  X="              x
Acos: procedure; arg x;  if x<-1 | x>1  then call AcosErr;      return .5 * pi() - Asin(x)
Atan: procedure; parse arg x; if abs(x)=1 then return pi()*x/4; return Asin(x/sqrt(1+x*x))
/*──────────────────────────────────────────────────────────────────────────────────────*/
Asin: procedure; parse arg x;   if x<-1 | x>1  then call AsinErr;    s= x*x
if abs(x)>=sqrt(2)*.5  then return sign(x) * Acos(sqrt(1-s));  z= x;  o= x;     p= z
do j=2 by 2; o= o*s*(j-1)/j; z=z+o/(j+1); if z=p  then leave; p= z;  end; return z
/*──────────────────────────────────────────────────────────────────────────────────────*/
sin:  procedure; parse arg x;        x= r2r(x);          numeric fuzz min(5, digits() - 3)
if abs(x)=pi  then return;              return .sinCos(x, x, 1)
/*──────────────────────────────────────────────────────────────────────────────────────*/
cos:  procedure; parse arg x;        x= r2r(x);          a= abs(x);          hpi= pi * .5
numeric fuzz min(6, digits() - 3);      if a=pi      then return -1
if a=hpi | a=hpi*3  then return 0;      if a=pi/3    then return .5
if a=pi * 2 / 3     then return '-.5';  return .sinCos(1, 1, '-1')
/*──────────────────────────────────────────────────────────────────────────────────────*/
.sinCos: parse arg z,!,i;                  x= x*x;                     p= z
do #=2 by 2; != -!*x/(#*(#+i)); z= z+!; if z=p  then leave; p= z; end; return z
/*──────────────────────────────────────────────────────────────────────────────────────*/
civil:      select                               /* [↓]  Maybe below  Antarctic circle, */
when h== 0  then hc= 'midnight'      /*        or  above     Arctic    "    */
when h <12  then hc=    h  'am'      /*convert da hour for human beans (sic)*/
when h==12  then hc= 'noon'          /*   ···  easier to understand now.    */
when h >0   then hc=    h  'pm'      /*   ···  even more meaningful.        */
end   /*select*/
parse var hc  hh ampm .;    if \datatype(hh, 'N')  then return     /*not numeric? */
hh= hh / 1;   if hh>12  then hh= hh - 12                           /*civil time ? */
if pos(., hh)==0  then do; hc= right(hh, 2)'   ' ampm; return; end /*exact hour ? */
parse var  hh   hr '.' -0 mn;  if hr==0  then hr= 12               /*get MN; noon?*/
mn= mn * 60 / 1;  hc= right(hr, 2)":"right(mn, 2, 0) ampm; return  /*reformat time*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
sqrt: procedure; parse arg x;  if x=0  then return 0;  d=digits();  numeric digits;  h=d+6
m.=9; numeric form; parse value format(x,2,1,,0) 'E0' with g 'E' _ .; g=g*.5'e'_ % 2
do j=0  while h>9;      m.j= h;             h= h % 2 + 1;    end  /*j*/
do k=j+5  to 0  by -1;  numeric digits m.k; g= (g+x/g) *.5;  end  /*k*/;  return g
```
output   when using the default inputs:
```       latitude:  -4.95
longitude: -150.5
legal meridian:   -150
sun hour   dial hour
hour       angle    line angle
══════════ ══════════ ════════════
5    am    -104.5      161.5
5:15 am    -100.8      155.6
5:30 am     -97.0      144.9
5:45 am     -93.3      123.3
6    am     -89.5       84.2
6:15 am     -85.8       49.3
6:30 am     -82.0       31.5
6:45 am     -78.3       22.5
7    am     -74.5       17.3
7:15 am     -70.8       13.9
7:30 am     -67.0       11.5
7:45 am     -63.3        9.7
8    am     -59.5        8.3
8:15 am     -55.8        7.2
8:30 am     -52.0        6.3
8:45 am     -48.3        5.5
9    am     -44.5        4.8
9:15 am     -40.8        4.3
9:30 am     -37.0        3.7
9:45 am     -33.3        3.2
10    am     -29.5        2.8
10:15 am     -25.8        2.4
10:30 am     -22.0        2.0
10:45 am     -18.3        1.6
11    am     -14.5        1.3
11:15 am     -10.8        0.9
11:30 am      -7.0        0.6
11:45 am      -3.3        0.3
12    pm       0.5        0.0
12:15 pm       4.3       -0.4
12:30 pm       8.0       -0.7
12:45 pm      11.8       -1.0
1    pm      15.5       -1.4
1:15 pm      19.3       -1.7
1:30 pm      23.0       -2.1
1:45 pm      26.8       -2.5
2    pm      30.5       -2.9
2:15 pm      34.3       -3.4
2:30 pm      38.0       -3.9
2:45 pm      41.8       -4.4
3    pm      45.5       -5.0
3:15 pm      49.3       -5.7
3:30 pm      53.0       -6.5
3:45 pm      56.8       -7.5
4    pm      60.5       -8.7
4:15 pm      64.3      -10.1
4:30 pm      68.0      -12.1
4:45 pm      71.8      -14.7
5    pm      75.5      -18.5
5:15 pm      79.3      -24.4
5:30 pm      83.0      -35.1
5:45 pm      86.8      -56.7
6    pm      90.5      -95.8
6:15 pm      94.3     -130.7
6:30 pm      98.0     -148.5
6:45 pm     101.8     -157.5
7    pm     105.5     -162.7
══════════ ══════════ ════════════
```

## Ring

```# Project : Horizontal sundial calculations

pi = 22/7
decimals(3)

latitude = -4.95
longitude = -150.5
meridian = -150.0

see "enter latitude (degrees): " + latitude + nl
see "enter longitude (degrees): " + longitude + nl
see "enter legal meridian (degrees): " + meridian + nl

see "time   " + "   sun hour angle" + "      dial hour line angle" + nl

for hour = 6 to 18
hra = 15*hour - longitude + meridian - 180
hla = 180/pi*(atan(sin(pi/180*latitude) * tan(pi/180*hra)))
if fabs(hra) > 90
hla = hla + 180 * sign(hra * latitude)
ok
see "" + hour + "           " + hra + "                  " + hla + nl
next```

Output:

```enter latitude (degrees): -4.950
enter longitude (degrees): -150.500
enter legal meridian (degrees): -150
time      sun hour angle      dial hour line angle
6           -89.500                  84.607
7           -74.500                  17.316
8           -59.500                  8.342
9           -44.500                  4.850
10           -29.500                  2.796
11           -14.500                  1.279
12           0.500                  -0.043
13           15.500                  -1.371
14           30.500                  -2.911
15           45.500                  -5.021
16           60.500                  -8.680
17           75.500                  -18.488
18           90.500                  -96.224
```

## Ruby

Translation of: ALGOL 68
Translation of: Python
```include Math
DtoR = PI/180

print 'Enter latitude: '
lat = Float( gets )
print 'Enter longitude: '
lng = Float( gets )
print 'Enter legal meridian: '
ref = Float( gets )
puts

slat = sin( lat * DtoR )

puts "    sine of latitude:  %.3f"% slat
puts "    diff longitude:    %.3f"% (lng-ref)
puts
puts 'Hour, sun hour angle, dial hour line angle from 6am to 6pm'
-6.upto(6) do |h|
hra = 15 * h
hra -= lng - ref
hla =  atan( slat * tan( hra * DtoR ))/ DtoR
puts "HR =%3d; HRA =%7.3f; HLA =%7.3f" % [h, hra, hla]
end
```
Output:
```Enter latitude: -4.95
Enter longitude: -150.5
Enter legal meridian: -150

sine of latitude:  -0.086
diff longitude:    -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR = -6; HRA =-89.500; HLA = 84.225
HR = -5; HRA =-74.500; HLA = 17.283
HR = -4; HRA =-59.500; HLA =  8.334
HR = -3; HRA =-44.500; HLA =  4.847
HR = -2; HRA =-29.500; HLA =  2.795
HR = -1; HRA =-14.500; HLA =  1.278
HR =  0; HRA =  0.500; HLA = -0.043
HR =  1; HRA = 15.500; HLA = -1.371
HR =  2; HRA = 30.500; HLA = -2.910
HR =  3; HRA = 45.500; HLA = -5.018
HR =  4; HRA = 60.500; HLA = -8.671
HR =  5; HRA = 75.500; HLA =-18.451
HR =  6; HRA = 90.500; HLA = 84.225
```

## Rust

```use std::io;
struct SundialCalculation {
hour_angle: f64,
hour_line_angle: f64,
}

fn get_input(prompt: &str) -> Result<f64, Box<dyn std::error::Error>> {
println!("{}", prompt);
let mut input = String::new();
let stdin = io::stdin();
Ok(input.trim().parse::<f64>()?)
}

fn calculate_sundial(hour: i8, lat: f64, lng: f64, meridian: f64) -> SundialCalculation {
let diff = lng - meridian;
let hour_angle = f64::from(hour) * 15. - diff;
.atan()
.to_degrees();

SundialCalculation {
hour_angle,
hour_line_angle,
}
}
fn main() -> Result<(), Box<dyn std::error::Error>> {
let lat = get_input("Enter latitude       => ")?;
let lng = get_input("Enter longitude      => ")?;
let meridian = get_input("Enter legal meridian => ")?;
let diff = lng - meridian;

println!("Sine of latitude: {:.5}", sine_lat);
println!("Diff longitude: {}", diff);

println!("  Hrs Angle   Hour Line Angle");
(-6..=6).for_each(|hour| {
let sd = calculate_sundial(hour, lat, lng, meridian);
println!(
"{:>3}{} {:>5}   {:>+15.5}",
if hour == 0 { 12 } else { (hour + 12) % 12 },
if hour <= 6 { "pm" } else { "am" },
sd.hour_angle,
sd.hour_line_angle
);
});
Ok(())
}
```
Output:
```Enter latitude       =>
-4.95
Enter longitude      =>
-150.5
Enter legal meridian =>
-150
Sine of latitude: -0.08629
Diff longitude: -0.5
Hrs Angle   Hour Line Angle
6pm -89.5         +84.22483
7pm -74.5         +17.28293
8pm -59.5          +8.33371
9pm -44.5          +4.84671
10pm -29.5          +2.79487
11pm -14.5          +1.27835
12pm   0.5          -0.04314
1pm  15.5          -1.37079
2pm  30.5          -2.90964
3pm  45.5          -5.01802
4pm  60.5          -8.67140
5pm  75.5         -18.45100
6pm  90.5         +84.22483
```

## Sather

```class MAIN is

getvalue(s:STR):FLT is
#OUT + s + ": ";
return #FLT(#IN.get_line.str);
end;

dr(a:FLT):FLT is
return a * FLT::pi / 180.0;
end;

rd(a:FLT):FLT is
return a * 180.0 / FLT::pi;
end;

main is
lat ::= getvalue("Enter latitude");
lng ::= getvalue("Enter longitude");
ref ::= getvalue("Enter legal meridian");
#OUT + "\n";
slat ::= dr(lat).sin;
#OUT + "sine of latitude: " + #FMT("%.3f\n", slat);
#OUT + "diff longitude: " + #FMT("%.3f\n\n", lng - ref);
#OUT + "Hour, sun hour angle, dial hour line angle from 6am to 6pm\n";
loop h ::= (-6).upto!(6);
hra ::= 15.0 * h.flt;
hra := hra - lng + ref;
hla ::= rd((dr(hra).tan * slat).atan);
#OUT + #FMT("HR = %3d;  \t  HRA=%7.3f;  \t  HLA= %7.3f\n", h, hra, hla);
end;
end;
end;```

## Scala

```import java.util.Scanner

import scala.math.{atan2, cos, sin, toDegrees, toRadians}

object Sundial extends App {
var lat, slat,lng, ref = .0
val sc = new Scanner(System.in)
print("Enter latitude: ")
lat = sc.nextDouble
print("Enter longitude: ")
lng = sc.nextDouble
print("Enter legal meridian: ")
ref = sc.nextDouble
println()
println(f"sine of latitude: \$slat%.3f")
println(f"diff longitude: \${lng - ref}%.3f\n")
println("Hour, sun hour angle, dial hour line angle from 06h00 to 18h00")

for (h <- -6 to 6) {
val hra = 15.0 * h - lng + ref
println(f"HR= \$h%3d;\tHRA=\$hra%7.3f;\tHLA= \$hla%7.3f")
}

}
```

## Seed7

```\$ include "seed7_05.s7i";
include "float.s7i";
include "math.s7i";

const proc: main is func
local
var float: lat is 0.0;
var float: slat is 0.0;
var float: lng is 0.0;
var float: meridian is 0.0;
var float: hla is 0.0;
var float: hra is 0.0;
var integer: h is 0;
begin
write("Enter latitude: ");
write("Enter longitude: ");
write("Enter legal meridian: ");
writeln;
writeln("sine of latitude: " <& slat digits 3);
writeln("diff longitude: " <& lng - meridian digits 3);
writeln;
writeln("Hour, sun hour angle, dial hour line angle from 6am to 6pm");
for h range -6 to 6 do
hra := 15.0 * flt(h);
hra := hra - lng + meridian;
writeln("HR= " <& h lpad 2 <& "; HRA= " <& hra digits 3 lpad 7 <&
"; HLA= " <& hla digits 3 lpad 7);
end for;
end func;```
Output:
```Enter latitude: -4.95
Enter longitude: -150.5
Enter legal meridian: -150

sine of latitude: -0.086
diff longitude: -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.500; HLA=  84.225
HR= -5; HRA= -74.500; HLA=  17.283
HR= -4; HRA= -59.500; HLA=   8.334
HR= -3; HRA= -44.500; HLA=   4.847
HR= -2; HRA= -29.500; HLA=   2.795
HR= -1; HRA= -14.500; HLA=   1.278
HR=  0; HRA=   0.500; HLA=  -0.043
HR=  1; HRA=  15.500; HLA=  -1.371
HR=  2; HRA=  30.500; HLA=  -2.910
HR=  3; HRA=  45.500; HLA=  -5.018
HR=  4; HRA=  60.500; HLA=  -8.671
HR=  5; HRA=  75.500; HLA= -18.451
HR=  6; HRA=  90.500; HLA=  84.225```

## Sidef

Translation of: Raku
```var latitude  = read('Enter latitude       => ', Number)
var longitude = read('Enter longitude      => ', Number)
var meridian  = read('Enter legal meridian => ', Number)

var offset = (meridian - longitude)

say('Sine of latitude: ', "%.4f" % lat_sin)
say('Longitude offset: ', offset)
say('=' * 48)
say(' Hour  : Sun hour angle° : Dial hour line angle°')

for hour (-6 .. 6) {
var sun_deg  = (15*hour + offset)
atan2(
)
)
printf("%2d %s      %7.3f             %7.3f\n",
(hour + 12) % 12 || 12, (hour < 0 ? 'AM' : 'PM'), sun_deg, line_deg)
}
```
Output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150
Sine of latitude: -0.0863
Longitude offset: 0.5
================================================
Hour  : Sun hour angle° : Dial hour line angle°
6 AM      -89.500              84.225
7 AM      -74.500              17.283
8 AM      -59.500               8.334
9 AM      -44.500               4.847
10 AM      -29.500               2.795
11 AM      -14.500               1.278
12 PM        0.500              -0.043
1 PM       15.500              -1.371
2 PM       30.500              -2.910
3 PM       45.500              -5.018
4 PM       60.500              -8.671
5 PM       75.500             -18.451
6 PM       90.500             -95.775
```

## Smalltalk

Works with: GNU Smalltalk
```|lat slat lng ref hra hla pi|
pi := 1 arcTan * 4.
'Enter latitude:       ' display. lat := stdin nextLine asNumber.
'Enter longitude:      ' display. lng := stdin nextLine asNumber.
'Enter legal meridian: ' display. ref := stdin nextLine asNumber.
('sine of latitude: %1' % { slat }) displayNl.
('diff longitude: %1' % { lng - ref }) displayNl.

'Hour, sun hour angle, dial hour line angle from 6am to 6pm' displayNl.

-6 to: 6 do: [ :h |
hra := 15.0 * h.
hra := hra - lng + ref.
('HR= %1;  %4  HRA=%2;  %4  HLA= %3' % { h. hra. hla. \$<9> }) displayNl.
]
```

## Tcl

Translation of: ALGOL 68
```set PI 3.1415927
fconfigure stdout -buffering none
puts -nonewline "Enter latitude       => "; gets stdin lat
puts -nonewline "Enter longitude      => "; gets stdin lng
puts -nonewline "Enter legal meridian => "; gets stdin ref
puts ""

set slat [expr {sin(\$lat*\$PI/180)}]
puts [format "    sine of latitude:   %8g" \$slat]
puts [format "    diff longitude:     %3.3f" [expr {\$lng - \$ref}]]
puts ""
puts "Hour, sun hour angle, dial hour line angle from 6am to 6pm"

for {set h -6} {\$h<=6} {incr h} {
set hra [expr {15.0 * \$h}];      # hour angle is 15 times the hour #
set hra [expr {\$hra-\$lng+\$ref}]; # but correct for longitude difference #
set hla [expr {atan(\$slat * tan(\$hra*\$PI/180)) * 180/\$PI}]
puts [format "HR=%+3d; HRA=%+8.3f; HLA=%+8.3f" \$h \$hra \$hla]
}
```
Sample output:
```Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150

sine of latitude:   -0.0862864
diff longitude:     -0.500

Hour, sun hour angle, dial hour line angle from 6am to 6pm
HR= -6; HRA= -89.500; HLA= +84.225
HR= -5; HRA= -74.500; HLA= +17.283
HR= -4; HRA= -59.500; HLA=  +8.334
HR= -3; HRA= -44.500; HLA=  +4.847
HR= -2; HRA= -29.500; HLA=  +2.795
HR= -1; HRA= -14.500; HLA=  +1.278
HR= +0; HRA=  +0.500; HLA=  -0.043
HR= +1; HRA= +15.500; HLA=  -1.371
HR= +2; HRA= +30.500; HLA=  -2.910
HR= +3; HRA= +45.500; HLA=  -5.018
HR= +4; HRA= +60.500; HLA=  -8.671
HR= +5; HRA= +75.500; HLA= -18.451
HR= +6; HRA= +90.500; HLA= +84.225
```

## Wren

Translation of: Go
Library: Wren-fmt
```import "io" for Stdin, Stdout
import "./fmt" for Fmt

var getNum = Fn.new { |prompt|
while (true) {
System.write(prompt)
Stdout.flush()
var n = Num.fromString(input)
if (n) return n
System.print("Invalid number, try again.")
}
}

var lat = getNum.call("Enter latitude       : ")
var lng = getNum.call("Enter longitude      : ")
var ref = getNum.call("Enter legal meridian : ")
var slat = (lat * Num.pi / 180).sin
var diff = lng - ref
System.print("\n    sine of latitude : %(slat)")
System.print("    diff longitude   : %(diff)")
System.print("\nHour, sun hour angle, dial hour line angle from 6am to 6pm")
for (h in -6..6) {
var hra = 15*h - diff
var s = (hra * Num.pi /180).sin
var c = (hra * Num.pi /180).cos
var hla = (slat*s).atan(c) * 180 / Num.pi
Fmt.print("\$2.0f \$8.3f \$8.3f", h, hra, hla)
}
```
Output:
```Enter latitude       : -4.95
Enter longitude      : -150.5
Enter legal meridian : -150

sine of latitude : -0.086286365797923
diff longitude   : -0.5

Hour, sun hour angle, dial hour line angle from 6am to 6pm
-6  -89.500   84.225
-5  -74.500   17.283
-4  -59.500    8.334
-3  -44.500    4.847
-2  -29.500    2.795
-1  -14.500    1.278
0    0.500   -0.043
1   15.500   -1.371
2   30.500   -2.910
3   45.500   -5.018
4   60.500   -8.671
5   75.500  -18.451
6   90.500  -95.775
```

## x86 Assembly

Works with: nasm
Library: libc

It must be linked with the C standard library and startup code.

```	global main
extern printf, scanf

section .text

getvalue:
push	edx
push	eax
call	printf
push	in_ft
call	scanf
ret

st0dr:
fld	qword [drfact]
fmul
ret

main:
lea	eax, [lat_t]
lea	edx, [lat]
call    getvalue
lea	eax, [lng_t]
lea	edx, [lng]
call	getvalue
lea	eax, [ref_t]
lea	edx, [ref]
call	getvalue

push	newline
call	printf

fld	qword [lat]
call	st0dr
fsin
fst	qword [slat]

sub	esp, 8
fstp	qword [esp]
push	sin_ft
call	printf

fld	qword [lng]
fld	qword [ref]
fsubr	st0, st1
sub	esp, 8
fstp	qword [esp]
push	diff_ft
call	printf

push	tab_t
call	printf

mov	ecx, -6
.loop:
cmp	ecx, 6
jg	.endloop

push	ecx
fild	dword [esp]
fld	qword [xv]
fmulp
fld	qword [lng]
fsubp
fld	qword [ref]
pop	ecx

sub	esp, 20
mov	dword [esp], ecx
fst	qword [esp+4]

call	st0dr

fptan
fxch
fld	qword [slat]
fmulp
fxch
fpatan

fld	qword [rdinv]
fmul

fstp	qword [esp+12]

push	o_ft
call	printf
mov	ecx, [esp+4]

inc	ecx
jmp	.loop
.endloop:

xor	eax, eax
ret

section .data

lat:	dq	0.0
lng:	dq	0.0
ref:	dq	0.0
xv:	dq	15.0
slat:	dq	0.0
drfact:	dq	0.01745329251994329576
rdinv:	dq	57.29577951308232090712

section .rodata

lat_t:	db "Enter latitude: ", 0
lng_t:	db "Enter longitude: ", 0
ref_t:	db "Enter legal meridian: ", 0

in_ft:	db "%lf", 0
newline:
db 10, 0

sin_ft:
db "sine of latitude: %.3f", 10, 0
diff_ft:
db "diff longitude: %.3f", 10, 10, 0

tab_t:
db "Hour, sun hour angle, dial hour line angle from 6am to 6pm", 10, 0

o_ft:
db "HR= %3d;  ",9,"  HRA=%7.3f;  ",9,"  HLA= %7.3f", 10, 0
```

## XPL0

```inc  c:\cxpl\codes;
def  Pi = 3.14159265358979323846,
Tab = \$09;
real Lat, SinLat, Long, Mer;
real HA, HLA;                   \hour angle and hour line angle
int  H, T;                      \hour, time
[Text(0, "Latitude:       ");  Lat:=  RlIn(0);
Text(0, "Longitude:      ");  Long:= RlIn(0);
Text(0, "Legal meridian: ");  Mer:=  RlIn(0);
Text(0, "
Hour  Sun hour angle   Dial hour line angle
");
Format(4, 3);
for H:= -6 to 6 do
[HA:= float(15 * H);         \hour angle is 15 times the hour
HA:= HA - (Long-Mer);       \ but corrected for longitude difference
T:= H+12;  if T>12 then T:= T-12;
if T<10 then ChOut(0, ^ );  IntOut(0, T);
Text(0, if H>=0 then "pm    " else "am      ");
RlOut(0, HA);  ChOut(0, Tab);  RlOut(0, HLA);  CrLf(0);
];
]```
Output:
```Latitude:       -4.95
Longitude:      -150.5
Legal meridian: -150

Hour  Sun hour angle   Dial hour line angle
6am     -89.500          84.225
7am     -74.500          17.283
8am     -59.500           8.334
9am     -44.500           4.847
10am     -29.500           2.795
11am     -14.500           1.278
12pm       0.500          -0.043
1pm      15.500          -1.371
2pm      30.500          -2.910
3pm      45.500          -5.018
4pm      60.500          -8.671
5pm      75.500         -18.451
6pm      90.500         -95.775
```

## zkl

Translation of: F#
```//(degree measure)*Degrees => Radian measure
const pi=(0.0).pi, toDeg=(0.0).pi/180;

sineLatitude:=(latitude * toDeg).sin();
Console.writeln();
Console.writeln("Sine of latitude: ",sineLatitude);
Console.writeln("Difference of Longitudes (given longitude - meridian): ",longitude-meridian);
Console.writeln();

println("Numbers from 6 AM to 6 PM: ");
println("Hour\t\tSun hour angle\t Dial hour line angle");

foreach hour in ([-6..6]){
clockHour:=( if(hour < 0) "%sAM".fmt(hour.abs()) else "%sPM".fmt(hour) );
shr      :=15.0*hour - (longitude - meridian);
dhla     :=(sineLatitude*(shr*toDeg).tan()).atan()/toDeg;
Console.writeln("%s\t\t%5.1f\t\t%+7.3f".fmt(clockHour,shr,dhla));
}```
Output:
```\$ zkl bbb -4.95 -150.5 -150

Sine of latitude: -0.0862864
Difference of Longitudes (given longitude - meridian): -0.5

Numbers from 6 AM to 6 PM:
Hour		Sun hour angle	 Dial hour line angle
6AM		-89.5		+84.225
5AM		-74.5		+17.283
4AM		-59.5		 +8.334
3AM		-44.5		 +4.847
2AM		-29.5		 +2.795
1AM		-14.5		 +1.278
0PM		  0.5		 -0.043
1PM		 15.5		 -1.371
2PM		 30.5		 -2.910
3PM		 45.5		 -5.018
4PM		 60.5		 -8.671
5PM		 75.5		-18.451
6PM		 90.5		+84.225
```
Output:
```\$ zkl bbb -4.95
Enter longitude: -150.5
Enter legal meridian: -150
<as above>
```