SIMPLE SOLUTIONS

CATAN, CATANF, CATANL - reference manual online

Complex arc tangents.

Chapter
2015-04-19
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). ┌────────────────────────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├────────────────────────────┼───────────────┼─────────┤ │catan(), catanf(), catanl() │ 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 4.04 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 http://www.kernel.org/doc/man-pages/.
2015-04-19 CATAN(3)
This manual Reference Other manuals
catan(3) referred by atan(3) | complex(7) | ctan(3)
refer to attributes(7) | ccos(3) | clog(3) | complex(7) | ctan(3)