c/numeric/complex/cproj

@1-3@ Computes the projection of on the Riemann sphere. @4@ Type-generic macro: if has type, , or ,  is called. If  has type, , or ,  is called. If has type, , , or any integer type,  is called.

For most, , but all complex infinities, even the numbers where one component is infinite and the other is NaN, become positive real infinity, or. The sign of the imaginary (zero) component is the sign of.

Return value
The projection of on the Riemann sphere.

This function is fully specified for all possible inputs and is not subject to any errors described in math_errhandling