Absolute Value

Compute the absolute value of a single-precision floating-point number.

The absolute value is defined as

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

Usage

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

absf( x )

Computes the absolute value of a single-precision floating-point number.

var v = absf( -1.0 );
// returns 1.0

v = absf( 2.0 );
// returns 2.0

v = absf( 0.0 );
// returns 0.0

v = absf( -0.0 );
// returns 0.0

v = absf( NaN );
// returns NaN

Examples

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

var rand;
var i;

for ( i = 0; i < 100; i++ ) {
    rand = round( randu() * 100.0 ) - 50.0;
    console.log( 'absf(%d) = %d', rand, absf( rand ) );
}

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C APIs

Usage

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

stdlib_base_absf( x )

Computes the squared absolute value of a single-precision floating-point number.

float y = stdlib_base_absf( -5.0f );
// returns 5.0f

The function accepts the following arguments:

• x: [in] float input value.

float stdlib_base_absf( const float x );

Examples

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

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

    float y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_absf( x[ i ] );
        printf( "|%f| = %f\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.
• @stdlib/math/base/special/abs2f: compute the squared absolute value of a single-precision floating-point number.
• @stdlib/math/base/special/labs: compute an absolute value of a signed 32-bit integer.