_cabs

Calculates the absolute value of a complex number.

double_cabs(struct_complexz**);**

For additional compatibility information, see Compatibility in the Introduction.

Libraries

Return Value

_cabs returns the absolute value of its argument if successful. On overflow _cabs returns HUGE_VAL and sets errno to ERANGE. You can change error handling with _matherr.

Parameter

z

Complex number

Remarks

The _cabs function calculates the absolute value of a complex number, which must be a structure of type _complex. The structure z is composed of a real component x and an imaginary component y. A call to _cabs produces a value equivalent to that of the expression sqrt(z.x*z.x + z.y*z.y).

Example

/* CABS.C: Using _cabs, this program calculates
 * the absolute value of a complex number.
 */
#include <math.h>
#include <stdio.h>

void main( void )
{
   struct _complex number = { 3.0, 4.0 };
   double d;

   d = _cabs( number );
   printf( "The absolute value of %f + %fi is %f\n",
           number.x, number.y, d );
}

Output
The absolute value of 3.000000 + 4.000000i is 5.000000

Floating-Point Support Routines

See Also   abs, fabs, labs