Angle difference between two bearings: Difference between revisions

=={{header|Pascal}}==

This program is meant to be saved in the same folder as a file <code>angles.txt</code> containing the input. Each pair of angles to subtract appears on its own line in the input file.

<lang Pascal>

Program Bearings;

{ Reads pairs of angles from a file and subtracts them }

Const

fileName = 'angles.txt';

Type

degrees = real;

Var

subtrahend, minuend: degrees;

angleFile: text;

function Simplify(angle: degrees): degrees;

{ Returns an number in the range [-180.0, 180.0] }

begin

while angle > 180.0 do

angle := angle - 360.0;

while angle < -180.0 do

angle := angle + 360.0;

Simplify := angle

end;

function Difference(b1, b2: degrees): degrees;

{ Subtracts b1 from b2 and returns a simplified result }

begin

Difference := Simplify(b2 - b1)

end;

procedure Subtract(b1, b2: degrees);

{ Subtracts b1 from b2 and shows the whole equation onscreen }

var

b3: degrees;

begin

b3 := Difference(b1, b2);

writeln(b2:20:11, ' - ', b1:20:11, ' = ', b3:20:11)

end;

Begin

assign(angleFile, fileName);

reset(angleFile);

while not eof(angleFile) do

begin

readln(angleFile, subtrahend, minuend);

Subtract(subtrahend, minuend)

end;

close(angleFile)

End.

</lang>

{{in}}

20 45

-45 45

-85 90

-95 90

-45 125

-45 145

29.4803 -88.6381

-78.3251 -159.036

-70099.74233810938 29840.67437876723

-165313.6666297357 33693.9894517456

1174.8380510598456 -154146.66490124757

60175.77306795546 42213.07192354373

{{out}}

45.00000000000 - 20.00000000000 = 25.00000000000

45.00000000000 - -45.00000000000 = 90.00000000000

90.00000000000 - -85.00000000000 = 175.00000000000

90.00000000000 - -95.00000000000 = -175.00000000000

125.00000000000 - -45.00000000000 = 170.00000000000

145.00000000000 - -45.00000000000 = -170.00000000000

-88.63810000000 - 29.48030000000 = -118.11840000000

-159.03600000000 - -78.32510000000 = -80.71090000000

29840.67437876723 - -70099.74233810938 = -139.58328312339

33693.98945174560 - -165313.66662973570 = -72.34391851869

-154146.66490124760 - 1174.83805105985 = -161.50295230740

42213.07192354373 - 60175.77306795546 = 37.29885558827