Identity Function

Evaluate the identity function of a single-precision floating-point number.

The identity-function is defined as

for all x.

Usage

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

identityf( x )

Evaluates the identity function for a single-precision floating-point number.

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

v = identityf( 2.0 );
// returns 2.0

v = identityf( 0.0 );
// returns 0.0

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

v = identityf( NaN );
// returns NaN

Examples

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

var rand;
var i;

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

C APIs

Usage

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

stdlib_base_identityf( x )

Evaluates the identity function for a single-precision floating-point number.

float y = stdlib_base_identityf( 2.0f );
// returns 2.0f

The function accepts the following arguments:

x: [in] float input value.

float stdlib_base_identityf( const float x );

Examples

#include "stdlib/math/base/special/identityf.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_identityf( x[ i ] );
        printf( "f(%f) = %f\n", x[ i ], y );
    }
}