Arithmetic/Complex: Difference between revisions

=={{header|Pascal}}==

<pascal>

program showcomplex(output);

type

complex = record

re,im: real

end;

var

z1, z2, zr: complex;

procedure set(var result: complex; re, im: real);

begin

result.re := re;

result.im := im

end;

procedure print(a: complex);

begin

write('(', a.re , ',', a.im, ')')

end;

procedure add(var result: complex; a, b: complex);

begin

result.re := a.re + b.re;

result.im := a.im + b.im;

end;

procedure neg(var result: complex; a: complex);

begin

result.re := -a.re;

result.im := -a.im

end;

procedure mult(var result: complex; a, b: complex);

begin

result.re := a.re*b.re - a.im*b.im;

result.im := a.re*b.im + a.im*b.re

end;

procedure inv(var result: complex; a: complex);

var

anorm: real;

begin

anorm := a.re*a.re + a.im*a.im;

result.re := a.re/anorm;

result.im := -a.im/anorm

end;

begin

set(z1, 3, 4);

set(z2, 5, 6);

neg(zr, z1);

print(zr); { prints (-3,-4) }

writeln;

add(zr, z1, z2);

print(zr); { prints (8,10) }

writeln;

inv(zr, z1);

print(zr); { prints (0.12,-0.16) }

writeln;

mul(zr, z1, z2);

print(zr); { prints (-9,38) }

writeln

end.

</pascal>