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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¶
The catan() function calculates 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.
CONFORMING TO¶
C99.
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¶
COLOPHON¶
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.
2011-09-15 |