newlib/libm/complex/cabs.c

   1 /* $NetBSD: cabs.c,v 1.1 2007/08/20 16:01:30 drochner Exp $ */
   2
   3 /*
   4  * Written by Matthias Drochner <drochner@NetBSD.org>.
   5  * Public domain.
   6  *
   7  * imported and modified include for newlib 2010/10/03
   8  * Marco Atzeri <marco_atzeri@yahoo.it>
   9  */
  10
  11 /*
  12 FUNCTION
  13         <<cabs>>, <<cabsf>>, <<cabsl>>---complex absolute-value
  14
  15 INDEX
  16         cabs
  17 INDEX
  18         cabsf
  19 INDEX
  20         cabsl
  21
  22 SYNOPSIS
  23        #include <complex.h>
  24        double cabs(double complex <[z]>);
  25        float cabsf(float complex <[z]>);
  26        long double cabsl(long double complex <[z]>);
  27
  28
  29 DESCRIPTION
  30         These functions compute compute the complex absolute value
  31         (also called norm, modulus, or magnitude) of <[z]>.
  32
  33         <<cabsf>> is identical to <<cabs>>, except that it performs
  34         its calculations on <<float complex>>.
  35
  36         <<cabsl>> is identical to <<cabs>>, except that it performs
  37         its calculations on <<long double complex>>.
  38
  39 RETURNS
  40         The cabs* functions return the complex absolute value.
  41
  42 PORTABILITY
  43         <<cabs>>, <<cabsf>> and <<cabsl>> are ISO C99
  44
  45 QUICKREF
  46         <<cabs>>, <<cabsf>> and <<cabsl>> are ISO C99
  47
  48 */
  49
  50
  51 #include <complex.h>
  52 #include <math.h>
  53
  54 double
  55 cabs(double complex z)
  56 {
  57
  58         return hypot( creal(z), cimag(z) );
  59 }