Horizontal sundial calculations: Difference between revisions

=={{header|Seed7}}==

<lang seed7>$ include "seed7_05.s7i";

include "float.s7i";

include "math.s7i";

const float: radianToDegrees is 57.295779513082320876798154814114;

const float: degreesToRadian is 0.017453292519943295769236907684883;

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: ");

readln(lat);

write("Enter longitude: ");

readln(lng);

write("Enter legal meridian: ");

readln(meridian);

writeln;

slat := sin(degreesToRadian * lat);

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;

hla := radianToDegrees * atan(slat * tan(degreesToRadian * hra));

writeln("HR= " <& h lpad 2 <& "; HRA= " <& hra digits 3 lpad 7 <&

"; HLA= " <& hla digits 3 lpad 7);

end for;

end func;</lang>

Output:

<pre>

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

</pre>