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_cabs

Calculates the absolute value of a complex number.

double_cabs(struct_complexz**);**

Routine Required Header Compatibility
_cabs <math.h> Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version

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