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Absolute Value

Compute an absolute value of a signed 32-bit integer.

The absolute value is defined as

$$|x| = \begin{cases} x & \textrm{if}\ x \geq 0 \\ -x & \textrm{if}\ x < 0\end{cases}$$

Installation

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

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

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

labs( x )

Computes an absolute value of a signed 32-bit integer.

var v = labs( -1|0 );
// returns 1

v = labs( 2|0 );
// returns 2

v = labs( 0|0 );
// returns 0

Notes

• The implementation assumes two's complement.

• In two's complement systems, the absolute value of the minimum signed 32-bit integer is out-of-range. The absolute value for the minimum signed 32-bit integer is thus undefined.

  // -2^31
  var x = -2147483648|0;
  
  var v = labs( x );
  // returns -2147483648

Examples

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

var x;
var i;

for ( i = 0; i < 100; i++ ) {
    x = round( randu() * 100.0 ) - 50;
    console.log( 'abs(%d) = %d', x, labs( x|0 ) );
}

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C APIs

Usage

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

stdlib_base_labs( x )

Computes the absolute value of a signed 32-bit integer in two's complement format.

#include <stdint.h>

int32_t y = stdlib_base_labs( -5 );
// returns 5

The function accepts the following arguments:

• x: [in] int32_t input value.

int32_t stdlib_base_labs( const int32_t x );

Examples

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

int main( void ) {
    const int32_t x[] = { 3, -3, 0, -10 };

    int32_t y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_labs( x[ i ] );
        printf( "|%i| = %i\n", x[ i ], y );
    }
}

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See Also

• @stdlib/math-base/special/abs: compute the absolute value of a double-precision floating-point number.

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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

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.