1CPROJ(3)                   Linux Programmer's Manual                  CPROJ(3)
2
3
4

NAME

6       cproj, cprojf, cprojl - project into Riemann Sphere
7

SYNOPSIS

9       #include <complex.h>
10
11       double complex cproj(double complex z);
12       float complex cprojf(float complex z);
13       long double complex cprojl(long double complex z);
14
15       Link with -lm.
16

DESCRIPTION

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

VERSIONS

25       These functions first appeared in glibc in version 2.1.
26

ATTRIBUTES

28       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
29       tributes(7).
30
31       ┌────────────────────────────────────────────┬───────────────┬─────────┐
32       │Interface                                   │ Attribute     │ Value   │
33       ├────────────────────────────────────────────┼───────────────┼─────────┤
34       │cproj(), cprojf(), cprojl()                 │ Thread safety │ MT-Safe │
35       └────────────────────────────────────────────┴───────────────┴─────────┘
36

CONFORMING TO

38       C99, POSIX.1-2001, POSIX.1-2008.
39

NOTES

41       In glibc 2.11 and earlier, the implementation does something  different
42       (a stereographic projection onto a Riemann Sphere).
43

SEE ALSO

45       cabs(3), complex(7)
46

COLOPHON

48       This  page  is  part of release 5.12 of the Linux man-pages project.  A
49       description of the project, information about reporting bugs,  and  the
50       latest     version     of     this    page,    can    be    found    at
51       https://www.kernel.org/doc/man-pages/.
52
53
54
55                                  2021-03-22                          CPROJ(3)