@stdlib/math-base-special-cabs2f NPM

cabs2f

$NPM version$ $Build Status$ $Coverage Status$

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.

Installation

npm install @stdlib/math-base-special-cabs2f

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-ctor' );

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() over cabsf().

Examples

var Complex64 = require( '@stdlib/complex-float32-ctor' );
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( void ) {
    const 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 );
    }
}

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.