time-to-botec/squiggle/node_modules/@stdlib/math/base/special/labs/README.md

Absolute Value

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

The absolute value is defined as

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 ) );
}

---

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() {
    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 );
    }
}