/C

# cabsf, cabs, cabsl

Defined in header <complex.h>
float       cabsf( float complex z );
(1) (since C99)
double      cabs( double complex z );
(2) (since C99)
long double cabsl( long double complex z );
(3) (since C99)
Defined in header <tgmath.h>
#define fabs( z )
(4) (since C99)
1-3) Computes the complex absolute value (also known as norm, modulus, or magnitude) of z.
4) Type-generic macro: if z has type long double complex or long double imaginary, cabsl is called. If z has type float complex or float imaginary, cabsf is called. If z has type double complex or double imaginary, cabs is called. For real and integer types, the corresponding version of fabs is called.

### Parameters

 z - complex argument

### Return value

If no errors occur, returns the absolute value (norm, magnitude) of z.

Errors and special cases are handled as if the function is implemented as hypot(creal(z), cimag(z)).

### Example

#include <stdio.h>
#include <complex.h>

int main(void)
{
double complex z = 1.0 + 1.0*I;
printf("%.1f%+.1fi cartesian is rho=%f theta=%f polar\n",
creal(z), cimag(z), cabs(z), carg(z));
}

Output:

1.0+1.0i cartesian is rho=1.414214 theta=0.785398 polar
• C11 standard (ISO/IEC 9899:2011):
• 7.3.8.1 The cabs functions (p: 195)
• 7.25 Type-generic math <tgmath.h> (p: 373-375)
• G.7 Type-generic math <tgmath.h> (p: 545)
• C99 standard (ISO/IEC 9899:1999):
• 7.3.8.1 The cabs functions (p: 177)
• 7.22 Type-generic math <tgmath.h> (p: 335-337)
• G.7 Type-generic math <tgmath.h> (p: 480)

 cargcargfcargl (C99)(C99)(C99) computes the phase angle of a complex number (function) abslabsllabs (C99) computes absolute value of an integral value ($$\small{|x|}$$|x|) (function) fabsfabsffabsl (C99)(C99) computes absolute value of a floating-point value ($$\small{|x|}$$|x|) (function) hypothypotfhypotl (C99)(C99)(C99) computes square root of the sum of the squares of two given numbers ($$\scriptsize{\sqrt{x^2+y^2} }$$√x2+y2) (function) C++ documentation for abs