Calculates the absolute value of a complex number.
double _cabs( struct _complex z );
| 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