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catan(3) | Library Functions Manual | catan(3) |
NAME¶
catan, catanf, catanl - complex arc tangents
LIBRARY¶
Math library (libm, -lm)
SYNOPSIS¶
#include <complex.h>
double complex catan(double complex z); float complex catanf(float complex z); long double complex catanl(long double complex z);
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)
ATTRIBUTES¶
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
catan (), catanf (), catanl () | Thread safety | MT-Safe |
STANDARDS¶
C11, POSIX.1-2008.
HISTORY¶
glibc 2.1. C99, POSIX.1-2001.
EXAMPLES¶
/* Link with "-lm" */ #include <complex.h> #include <stdio.h> #include <stdlib.h> #include <unistd.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(f), cimag(f));
exit(EXIT_SUCCESS); }
SEE ALSO¶
2023-03-30 | Linux man-pages 6.04 |