2.17 cproj, cprojf— Riemann sphere projection

Synopsis

     #include <complex.h>
     double complex cproj(double complex z);
     float complex cprojf(float complex z);
     

Description
These functions compute a projection of z onto the Riemann sphere: z projects to z except that all complex infinities (even those with one infinite part and one NaN part) project to positive infinity on the real axis. If z has an infinite part, then cproj(z) is equivalent to

INFINITY + I * copysign(0.0, cimag(z))

cprojf is identical to cproj, except that it performs its calculations on floats complex.