2.16 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.

Returns
The cproj functions return the value of the projection onto the Riemann sphere.

Portability
cproj and cprojf are ISO C99