cabsf, cabs, cabsl

< c‎ | numeric‎ | complex
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.


[edit] Parameters

z - complex argument

[edit] 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))

[edit] 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));


1.0+1.0i cartesian is rho=1.414214 theta=0.785398 polar

[edit] References

  • C11 standard (ISO/IEC 9899:2011):
  • 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):
  • The cabs functions (p: 177)
  • 7.22 Type-generic math <tgmath.h> (p: 335-337)
  • G.7 Type-generic math <tgmath.h> (p: 480)

[edit] See also

computes the phase angle of a complex number
computes absolute value of an integral value (|x|)
computes absolute value of a floating-point value (|x|)
computes square root of the sum of the squares of two given numbers (x2