catanh(3)

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

6       catanh, catanhf, catanhl - complex arc tangents hyperbolic
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SYNOPSIS

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

18       The  catanh() function calculates the complex arc hyperbolic tangent of
19       z.  If y = catanh(z), then z = ctanh(y).  The imaginary part  of  y  is
20       chosen in the interval [-pi/2,pi/2].
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22       One has:
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24           catanh(z) = 0.5 * (clog(1 + z) - clog(1 - z))
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VERSIONS

27       These functions first appeared in glibc in version 2.1.
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CONFORMING TO

30       C99.
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EXAMPLE

33       /* Link with "-lm" */
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35       #include <complex.h>
36       #include <stdlib.h>
37       #include <unistd.h>
38       #include <stdio.h>
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40       int
41       main(int argc, char *argv[])
42       {
43           double complex z, c, f;
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45           if (argc != 3) {
46               fprintf(stderr, "Usage: %s <real> <imag>\n", argv[0]);
47               exit(EXIT_FAILURE);
48           }
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50           z = atof(argv[1]) + atof(argv[2]) * I;
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52           c = catanh(z);
53           printf("catanh() = %6.3f %6.3f*i\n", creal(c), cimag(c));
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55           f = 0.5 * (clog(1 + z) - clog(1 - z));
56           printf("formula  = %6.3f %6.3f*i\n", creal(f2), cimag(f2));
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58           exit(EXIT_SUCCESS);
59       }
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COLOPHON

65       This  page  is  part of release 3.53 of the Linux man-pages project.  A
66       description of the project, and information about reporting  bugs,  can
67       be found at http://www.kernel.org/doc/man-pages/.
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71                                  2011-09-15                         CATANH(3)