Horizontal sundial calculations: Difference between revisions

=={{header|Pascal}}==

<lang 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

Write('Enter latitude: '); Read(lat);

Write('Enter longitude: '); Read(lng);

Write('Enter legal meridian: '); Read(ref);

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.</lang>