cpow(), cpowf(), cpowl() — Calculate the complex power

Standards

Standards / Extensions	C or C++	Dependencies
C99 Single UNIX Specification, Version 3	both	z/OS V1R7 a compiler that is designed to support C99

Format

#include <complex.h>

double complex cpow(double complex x, double complex y);
float complex cpowf(float complex x, float complex y);
long double complex cpowl(long double complex x, long double complex y);

General description

The cpow() family of functions computes the complex value of x to the power of y, with a branch cut for the first parameter along the negative real axis.

Note: The following table shows the viable formats for these functions. See IEEE binary floating-point for more information about IEEE Binary Floating-Point.

Function	Hex	IEEE
cpow	X	X
cpowf	X	X
cpowl	X	X

Returned value

The cpow() family of functions return the complex power value.

Example

/*
 *  This example illustrates the complex power of complex number 'z'
 */
#include <complex.h>
#include <stdio.h>

void main()
{
   long double complex zl=-0.5 + I*0.5,  zpowl=(long double complex)3.0;
   double complex zd=(double complex)zl, zpowd=(double complex)zpowl;
   float complex zf=(float complex)zd,   zpowf=(float complex)zpowl;

   long double resl;
   double resd;
   float resf;

   printf("Illustrates the cpow function. Expected result is 0.25 in all cases\n");
   resd = cpow(zd,zpowd);
   resf = cpowf(zf,zpowf);
   resl = cpowl(zl,zpowl);
   printf("\tcpow(%f + I*%f,%f + I*%f) = %f\n",creal(zd), cimag(zd),
                                               creal(zpowd), cimag(zpowd), resd);
   printf("\tcpowf(%f + I*%f,%f + I*%f) = %f\n",crealf(zd), cimagf(zd),
                                               crealf(zpowf), cimagf(zpowf), resf);
   printf("\tcpowl(%Lf + I*%Lf,%Lf + I*%Lf) = %Lf\n",creall(zl), cimagl(zl),
                                                creall(zpowl), cimagl(zpowl), resl);
}
Output

Illustrates the cpow function. Expected result is 0.25
        cpow(-0.500000 + I*0.500000,3.000000 + I*0.000000) = 0.250000
        cpowf(-0.500000 + I*0.500000,3.000000 + I*0.000000) = 0.250000
        cpowl(-0.500000 + I*0.500000,3.000000 + I*0.000000) = 0.250000

Related information