CARGSection: Linux Programmer's Manual (3)
Index | Return to Main Contents
NAMEcarg, cargf, cargl - calculate the complex argument
double carg(double complex z);
float cargf(float complex z);
long double cargl(long double complex z);
DESCRIPTIONThese 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 argument of z.
tan(carg(z)) = cimag(z) / creal(z)
RETURN VALUEThe return value is the range of [-pi,pi].
VERSIONSThese functions first appeared in glibc in version 2.1.
ATTRIBUTESFor an explanation of the terms used in this section, see attributes(7).
|carg(), cargf(), cargl()||Thread safety||MT-Safe|
CONFORMING TOC99, POSIX.1-2001, POSIX.1-2008.
SEE ALSOcabs(3), complex(7)
COLOPHONThis 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/.
Return to Main Contents