# include <stdio.h>
# include <math.h>
//
//  You must include complex.h in order to get the complex data type
//  and the associated complex mathematical functions.
//
# include <complex.h>

int main ( )
{
//
//  A complex number has "complex" data type.
//  A complex value can be defined by "x+y*I".
//
  complex a = { 1.0 + 2.0 * I};
  complex b = 3.0 * I;
  complex c;
  float d = 7.0;
  double e = 1.5E2;
  int f = 77;
//
//  Print the initial values.
//  A complex number is treated as a pair of real values.
//
  printf ( "\n" );
  printf ( "  Complex a = (%g,%g)\n", a );
  printf ( "  Complex b = (%g,%g)\n", b );
  printf ( "  Complex c = (%g,%g)\n", c );
  printf ( "  Float d = %g\n", d );
  printf ( "  Double e = %g\n", e );
  printf ( "  Int f = %i\n", f );
//
//  Do a few calculations and print.
//  CABS is the absolute value of a complex number.
//  CIMAG is the imaginary part (and CREAL is the real part)
//  CSIN is the sine, and so on.
//
  c = a * b;
  d = cabs ( a );
  e = cimag ( b );
  b = csin ( a );

  printf ( "  Complex c = a*b = (%g,%g)\n", c );
  printf ( "  Float d = cabs(a) = %g\n", d );
  printf ( "  Double e = cimag(b) = %g\n", e );
  printf ( "  Complex b = csin(a) = (%g,%g)\n", b );

  return;
}