cabs(3) - BetterMan

cabs(3)

absolute value of a complex number

distropkg manpages-dev@6.9.1-1dataset 2026-04-01T06:19:02Z+debian+ec4110e+mandoc:1.14.6-4

Synopsis

#include <complex.h>
double cabs(double complex 
z
);
float cabsf(float complex 
z
);
long double cabsl(long double complex 
z
);

—

NAME

cabs, cabsf, cabsl - absolute value of a complex number

Math library (libm, -lm)

bash

#include <complex.h>

bash

double cabs(double complex \nz\n);\n
\nfloat cabsf(float complex \nz\n);\n
\nlong double cabsl(long double complex \nz\n);

These functions return the absolute value of the complex number z. The result is a real number.

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
cabs (), cabsf (), cabsl ()	Thread safety	MT-Safe

C11, POSIX.1-2008.

glibc 2.1. C99, POSIX.1-2001.

The function is actually an alias for hypot(a, b) (or, equivalently, sqrt(a*a + b*b)).