projects / thirdparty / man-pages.git / blame
| Commit | Line | Data |
|---|---|---|
| a1eaacb1 | 1 | '\" t |
| fea681da | 2 | .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de) |
| 2297bf0e | 3 | .\" |
| 95fb8859 | 4 | .\" SPDX-License-Identifier: GPL-1.0-or-later |
| fea681da | 5 | .\" |
| 4c1c5274 | 6 | .TH clog 3 (date) "Linux man-pages (unreleased)" |
| fea681da MK |
7 | .SH NAME |
| 8 | clog, clogf, clogl \- natural logarithm of a complex number | |
| 2af19291 AC |
9 | .SH LIBRARY |
| 10 | Math library | |
| 8fc3b2cf | 11 | .RI ( libm ", " \-lm ) |
| fea681da | 12 | .SH SYNOPSIS |
| c7db92b9 | 13 | .nf |
| fea681da | 14 | .B #include <complex.h> |
| 68e4db0a | 15 | .PP |
| fea681da | 16 | .BI "double complex clog(double complex " z ); |
| fea681da | 17 | .BI "float complex clogf(float complex " z ); |
| fea681da | 18 | .BI "long double complex clogl(long double complex " z ); |
| c7db92b9 | 19 | .fi |
| fea681da | 20 | .SH DESCRIPTION |
| 7dffdbbd | 21 | These functions calculate the complex natural logarithm of |
| defcc338 MK |
22 | .IR z , |
| 23 | with a branch cut along the negative real axis. | |
| 847e0d88 | 24 | .PP |
| c1f2e990 MK |
25 | The logarithm |
| 26 | .BR clog () | |
| 27 | is the inverse function of the exponential | |
| 28 | .BR cexp (3). | |
| 658670de | 29 | Thus, if \fIy\ =\ clog(z)\fP, then \fIz\ =\ cexp(y)\fP. |
| c13182ef MK |
30 | The imaginary part of |
| 31 | .I y | |
| e17f9d28 | 32 | is chosen in the interval [\-pi,pi]. |
| dd3568a1 | 33 | .PP |
| 658670de | 34 | One has: |
| 207050fa | 35 | .PP |
| 1ae6b2c7 AC |
36 | .in +4n |
| 37 | .EX | |
| 38 | clog(z) = log(cabs(z)) + I * carg(z) | |
| 39 | .EE | |
| 40 | .in | |
| dd3568a1 | 41 | .PP |
| c13182ef MK |
42 | Note that |
| 43 | .I z | |
| 44 | close to zero will cause an overflow. | |
| 4e1c6675 MS |
45 | .SH ATTRIBUTES |
| 46 | For an explanation of the terms used in this section, see | |
| 47 | .BR attributes (7). | |
| 48 | .TS | |
| 49 | allbox; | |
| c466875e | 50 | lbx lb lb |
| 4e1c6675 MS |
51 | l l l. |
| 52 | Interface Attribute Value | |
| 53 | T{ | |
| 9e54434e BR |
54 | .na |
| 55 | .nh | |
| 4e1c6675 MS |
56 | .BR clog (), |
| 57 | .BR clogf (), | |
| 58 | .BR clogl () | |
| 59 | T} Thread safety MT-Safe | |
| 60 | .TE | |
| c466875e | 61 | .sp 1 |
| 3113c7f3 | 62 | .SH STANDARDS |
| 4131356c AC |
63 | C11, POSIX.1-2008. |
| 64 | .SH HISTORY | |
| 65 | glibc 2.1. | |
| 66 | C99, POSIX.1-2001. | |
| 47297adb | 67 | .SH SEE ALSO |
| fea681da MK |
68 | .BR cabs (3), |
| 69 | .BR cexp (3), | |
| 70 | .BR clog10 (3), | |
| 75398312 | 71 | .BR clog2 (3), |
| a8bda636 | 72 | .BR complex (7) |