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man:catanl

CATAN(3) Linux Programmer's Manual CATAN(3)

NAME

     catan, catanf, catanl - complex arc tangents

SYNOPSIS

     #include <complex.h>
     double complex catan(double complex z);
     float complex catanf(float complex z);
     long double complex catanl(long double complex z);
     Link with -lm.

DESCRIPTION

     These   functions   calculate   the  complex  arc  tangent  of  z.   If
     y = catan(z), then z = ctan(y).  The real part of y is  chosen  in  the
     interval [-pi/2,pi/2].
     One has:
         catan(z) = (clog(1 + i * z) - clog(1 - i * z)) / (2 * i)

VERSIONS

     These functions first appeared in glibc in version 2.1.

ATTRIBUTES

     For   an   explanation   of   the  terms  used  in  this  section,  see
     attributes(7).
     allbox; lbw27 lb lb  l  l  l.   Interface Attribute Value  T{  catan(),
     catanf(), catanl() T}   Thread safety  MT-Safe

CONFORMING TO

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

EXAMPLE

     /* Link with "-lm" */
     #include  <complex.h>  #include <stdlib.h> #include <unistd.h> #include
     <stdio.h>
     int main(int argc, char *argv[]) {
         double complex z, c, f;
         double complex i = I;
         if (argc != 3) {
             fprintf(stderr, "Usage: %s <real> <imag>\n", argv[0]);
             exit(EXIT_FAILURE);
         }
         z = atof(argv[1]) + atof(argv[2]) * I;
         c = catan(z);
         printf("catan() = %6.3f %6.3f*i\n", creal(c), cimag(c));
         f = (clog(1 + i * z) - clog(1 - i * z)) / (2 * i);
         printf("formula = %6.3f %6.3f*i\n", creal(f2), cimag(f2));
         exit(EXIT_SUCCESS); }

SEE ALSO

     ccos(3), clog(3), ctan(3), complex(7)

COLOPHON

     This page is part of release 4.16 of the Linux  man-pages  project.   A
     description  of  the project, information about reporting bugs, and the
     latest    version    of    this    page,    can     be     found     at
     https://www.kernel.org/doc/man-pages/.
                                2015-04-19                          CATAN(3)
/data/webs/external/dokuwiki/data/pages/man/catanl.txt · Last modified: 2019/05/17 09:32 by 127.0.0.1

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