cproj, cprojf, cprojl − project into Riemann Sphere

#include <complex.h>

double complex cproj(double complex z);

float complex cprojf(float complex z);

long double complex cprojl(long double complex z);

With this function you can project a point in the plane onto the surface of a Riemann Sphere, the one-point compactification of the complex plane. Each finite point z projects to z itself. Every complex infinite values is projected to a single infinite value, namely to positive infinity on the real axis.

C99

cabs(3)