@stdlib/math-base-special-copysign

What is @stdlib/math-base-special-copysign?

@stdlib/math-base-special-copysign is a utility for copying the sign of a number to another number. This can be useful in various mathematical computations where the sign of a number needs to be manipulated or transferred.

What are @stdlib/math-base-special-copysign's main functionalities?

Copying the sign of a number

This feature allows you to copy the sign of one number to another. In this example, the sign of `y` (-2.0) is copied to `x` (3.14), resulting in -3.14.

const copysign = require('@stdlib/math-base-special-copysign');

const x = 3.14;
const y = -2.0;
const result = copysign(x, y);
console.log(result); // -3.14

Other packages similar to @stdlib/math-base-special-copysign

mathjs

mathjs is a comprehensive math library for JavaScript and Node.js. It provides a wide range of mathematical functions, including the ability to manipulate the sign of numbers using the `math.sign` function. However, it is more feature-rich and general-purpose compared to @stdlib/math-base-special-copysign.

lodash

lodash is a popular utility library that provides various functions for common programming tasks, including mathematical operations. While lodash does not have a direct equivalent to `copysign`, it offers a wide range of utilities that can be used to achieve similar results through custom implementations.

README

About stdlib...

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When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

copysign

Return a double-precision floating-point number with the magnitude of x and the sign of y.

Installation

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

Usage

var copysign = require( '@stdlib/math-base-special-copysign' );

copysign( x, y )

Returns a double-precision floating-point number with the magnitude of x and the sign of y.

var z = copysign( -3.14, 10.0 );
// returns 3.14

z = copysign( 3.14, -1.0 );
// returns -3.14

z = copysign( 1.0, -0.0 );
// returns -1.0

z = copysign( -3.14, -0.0 );
// returns -3.14

z = copysign( -0.0, 1.0 );
// returns 0.0

Notes

• According to the IEEE754 standard, a NaN has a biased exponent equal to 2047, a significand greater than 0, and a sign bit equal to either 1 or 0. In which case, NaN may not correspond to just one but many binary representations. Accordingly, care should be taken to ensure that y is not NaN; otherwise, behavior may be indeterminate.

Examples

var randu = require( '@stdlib/random-base-randu' );
var copysign = require( '@stdlib/math-base-special-copysign' );

var x;
var y;
var z;
var i;

// Generate random double-precision floating-point numbers `x` and `y` and copy the sign of `y` to `x`...
for ( i = 0; i < 100; i++ ) {
    x = (randu()*100.0) - 50.0;
    y = (randu()*10.0) - 5.0;
    z = copysign( x, y );
    console.log( 'x: %d, y: %d => %d', x, y, z );
}

C APIs

Usage

#include "stdlib/math/base/special/copysign.h"

stdlib_base_copysign( x, y )

Returns a double-precision floating-point number with the magnitude of x and the sign of y.

double v = stdlib_base_copysign( -3.14, 10.0 );
// returns 3.14

double v = stdlib_base_copysign( 3.14, -1.0 );
// returns -3.14

The function accepts the following arguments:

• x: [in] double number from which to derive a magnitude.
• y: [in] double number from which to derive a sign.

double stdlib_base_copysign( const double x, const double y );

Examples

#include "stdlib/math/base/special/copysign.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { 3.14, -3.14, 0.0, 0.0/0.0 };

    double y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_copysign( x[ i ], -3.0 );
        printf( "copysign(%lf, %lf) = %lf\n", x[ i ], -3.0, y );
    }
}

See Also

• @stdlib/math-base/special/flipsign: return a double-precision floating-point number with the magnitude of x and the sign of x*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.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.

Changelog

0.2.2 (2024-07-28)

<section class="commits">

Commits

<details>

• 2777e4b - bench: resolve lint errors in benchmarks (by Athan Reines)
• 41d41e9 - test: include trailing newlines in Julia-generated JSON fixtures (by Philipp Burckhardt)
• 9ed7d0e - chore: add missing trailing newlines (by Philipp Burckhardt)

</details> </section> <!-- /.commits --> <section class="contributors">

Contributors

A total of 2 people contributed to this release. Thank you to the following contributors:

• Athan Reines
• Philipp Burckhardt

</section> <!-- /.contributors --> </section> <!-- /.release --> <section class="release" id="v0.2.1">