CREAL(3) Linux Programmer's Manual CREAL(3) NAME creal, crealf, creall - get real part of a complex number SYNOPSIS #include <complex.h> double creal(double complex z); float crealf(float complex z); long double creall(long double complex z); Link with -lm. DESCRIPTION These functions return the real part of the complex number z. One has: z = creal(z) + I * cimag(z) 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 │ ├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤ │creal(), crealf(), creall() │ Thread safety │ MT-Safe │ └──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘ CONFORMING TO C99, POSIX.1-2001, POSIX.1-2008. NOTES The gcc supports also __real__. That is a GNU extension. SEE ALSO cabs(3), cimag(3), complex(7) 2021-03-22 CREAL(3)