cabs2f
Compute the squared absolute value of a single-precision complex floating-point number.
The absolute value of a complex number is defined as
which corresponds to the length of a vector from the origin to a complex value plotted in the complex plane.
Usage
var cabs2f = require( '@stdlib/math/base/special/cabs2f' );
cabs2f( z )
Computes the squared absolute value of a single-precision complex floating-point number.
var Complex64 = require( '@stdlib/complex/float32' );
var y = cabs2f( new Complex64( 5.0, 3.0 ) );
// returns 34.0
Notes
- Be careful to avoid overflow and underflow.
- Depending on the environment, this function may have better performance than computing the absolute value of a complex number and then squaring. Hence, where appropriate, consider using
cabs2f()
overcabsf()
.
Examples
var Complex64 = require( '@stdlib/complex/float32' );
var discreteUniform = require( '@stdlib/random/base/discrete-uniform' ).factory;
var cabs2f = require( '@stdlib/math/base/special/cabs2f' );
// Create a PRNG to generate uniformly distributed pseudorandom integers:
var rand = discreteUniform( -50, 50 );
// Compute the squared absolute value for a set of random numbers...
var z;
var i;
for ( i = 0; i < 100; i++ ) {
z = new Complex64( rand(), rand() );
console.log( 'cabs2f(%s) = %d', z.toString(), cabs2f( z ) );
}
C APIs
Usage
#include "stdlib/math/base/special/cabs2f.h"
stdlib_base_cabs2f( z )
Computes the squared absolute value of a single-precision complex floating-point number.
#include <complex.h>
float y = stdlib_base_cabs2f( 5.0+3.0*I );
// returns 34.0f
The function accepts the following arguments:
- z:
[in] float complex
input value.
float stdlib_base_cabs2f( const float complex z );
Examples
#include "stdlib/math/base/special/cabs2f.h"
#include <stdio.h>
#include <complex.h>
int main() {
float complex x[] = { 3.14f+1.0f*I, -3.14f-1.0f*I, 0.0f+0.0f*I, 0.0f/0.0f+0.0f/0.0f*I };
float complex v;
float y;
int i;
for ( i = 0; i < 4; i++ ) {
v = x[ i ];
y = stdlib_base_cabs2f( v );
printf( "f(%f + %f) = %f\n", crealf( v ), cimagf( v ), y );
}
}