carg(3) Library Functions Manual carg(3) NAME carg, cargf, cargl - calculate the complex argument LIBRARY Math library (libm, -lm) SYNOPSIS #include <complex.h> double carg(double complex z); float cargf(float complex z); long double cargl(long double complex z); DESCRIPTION These functions calculate the complex argument (also called phase angle) of z, with a branch cut along the negative real axis. A complex number can be described by two real coordinates. One may use rectangular coordinates and gets z = x + I * y where x = creal(z) and y = cimag(z). Or one may use polar coordinates and gets z = r * cexp(I * a) where r = cabs(z) is the "radius", the "modulus", the absolute value of z, and a = carg(z) is the "phase angle", the argu‐ ment of z. One has: tan(carg(z)) = cimag(z) / creal(z) RETURN VALUE The return value is in the range of [-pi,pi]. VERSIONS These functions were added in glibc 2.1. ATTRIBUTES For an explanation of the terms used in this section, see attributes(7). ┌─────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├─────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤ │carg(), cargf(), cargl() │ Thread safety │ MT-Safe │ └─────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘ STANDARDS C99, POSIX.1-2001, POSIX.1-2008. SEE ALSO cabs(3), complex(7) Linux man-pages 6.03 2022-12-15 carg(3)