1CLOG(3)                    Linux Programmer's Manual                   CLOG(3)
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NAME

6       clog, clogf, clogl - natural logarithm of a complex number
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SYNOPSIS

9       #include <complex.h>
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11       double complex clog(double complex z);
12       float complex clogf(float complex z);
13       long double complex clogl(long double complex z);
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15       Link with -lm.
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DESCRIPTION

18       These  functions  calculate  the complex natural logarithm of z, with a
19       branch cut along the negative real axis.
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21       The logarithm  clog()  is  the  inverse  function  of  the  exponential
22       cexp(3).   Thus,  if y = clog(z), then z = cexp(y).  The imaginary part
23       of y is chosen in the interval [-pi,pi].
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25       One has:
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27           clog(z) = log(cabs(z)) + I * carg(z)
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29       Note that z close to zero will cause an overflow.
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VERSIONS

32       These functions first appeared in glibc in version 2.1.
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ATTRIBUTES

35       For an  explanation  of  the  terms  used  in  this  section,  see  at‐
36       tributes(7).
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38       ┌────────────────────────────────────────────┬───────────────┬─────────┐
39       │Interface                                   │ Attribute     │ Value   │
40       ├────────────────────────────────────────────┼───────────────┼─────────┤
41       │clog(), clogf(), clogl()                    │ Thread safety │ MT-Safe │
42       └────────────────────────────────────────────┴───────────────┴─────────┘
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CONFORMING TO

45       C99, POSIX.1-2001, POSIX.1-2008.
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SEE ALSO

48       cabs(3), cexp(3), clog10(3), clog2(3), complex(7)
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COLOPHON

51       This  page  is  part of release 5.13 of the Linux man-pages project.  A
52       description of the project, information about reporting bugs,  and  the
53       latest     version     of     this    page,    can    be    found    at
54       https://www.kernel.org/doc/man-pages/.
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58                                  2021-03-22                           CLOG(3)
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