Horizontal sundial calculations: Difference between revisions

=={{header|PicoLisp}}==

{{trans|ALGOL 68}}

<lang PicoLisp>(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 3))

(prinl " diff longitude: " (round (- Lng Ref) 3))

(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 3))

"; HLA="

(align 8 (round Hla 3)) ) ) ) ) ) )</lang>

Output:

<pre>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</pre>