cprojf(3)

1cproj(3)                   Library Functions Manual                   cproj(3)
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NAME

6       cproj, cprojf, cprojl - project into Riemann Sphere
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LIBRARY

9       Math library (libm, -lm)
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SYNOPSIS

12       #include <complex.h>
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14       double complex cproj(double complex z);
15       float complex cprojf(float complex z);
16       long double complex cprojl(long double complex z);
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DESCRIPTION

19       These functions project a point in the plane onto the surface of a Rie‐
20       mann Sphere, the one-point compactification of the complex plane.  Each
21       finite  point  z projects to z itself.  Every complex infinite value is
22       projected to a single infinite value, namely to  positive  infinity  on
23       the real axis.
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ATTRIBUTES

26       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
27       tributes(7).
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29       ┌────────────────────────────────────────────┬───────────────┬─────────┐
30       │Interface                                   │ Attribute     │ Value   │
31       ├────────────────────────────────────────────┼───────────────┼─────────┤
32       │cproj(), cprojf(), cprojl()                 │ Thread safety │ MT-Safe │
33       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

36       C11, POSIX.1-2008.
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HISTORY

39       glibc 2.1.  C99, POSIX.1-2001.
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41       In glibc 2.11 and earlier, the implementation does something  different
42       (a stereographic projection onto a Riemann Sphere).
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