====== creal ======
<code c>
double creal(double complex z);
</code>

==== description of creal ====
calculate the complex real part


<code c>
#include <stdio.h>
#include <complex.h>

int main( void )
{

   double complex zdouble=(double complex)4.24 + I*1.34;
   printf("creal(%f)\n", creal(zdouble));
   return 0;
}

</code>

===== output of creal c example =====
    creal(4.240000)