xlogyf

Compute x * ln(y) so that the result is 0 if x = 0 for single-precision floating-point numbers x and y.

Usage

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

xlogyf( x, y )

Computes x * ln(y) so that the result is 0 if x = 0 for single-precision floating-point numbers x and y.

var out = xlogyf( 3.0, 2.0 );
// returns ~2.079

out = xlogyf( 1.5, 5.9 );
// returns ~2.662

out = xlogyf( 0.9, 1.0 );
// returns 0.0

out = xlogyf( 0.0, -2.0 );
// returns 0.0

out = xlogyf( 1.5, NaN );
// returns NaN

out = xlogyf( 0.0, NaN );
// returns NaN

out = xlogyf( NaN, 2.3 );
// returns NaN

Examples

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

var x;
var y;
var i;

for ( i = 0; i < 100; i++ ) {
    x = randu();
    if ( x < 0.5 ) {
        x = 0.0;
    }
    y = ( randu() * 20.0 ) - 5.0;
    console.log( 'xlogyf(%d, %d) = %d', x, y, xlogyf( x, y ) );
}

C APIs

Usage

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

stdlib_base_xlogyf( x, y )

Computes x * ln(y) so that the result is 0 if x = 0 for single-precision floating-point numbers x and y.

float v = stdlib_base_xlogyf( 3.0f, 2.0f );
// returns ~2.079f

The function accepts the following arguments:

x: [in] float input value.
y: [in] float input value.

float stdlib_base_xlogyf( const float x, const float y );

Examples

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

int main( void ) {
    float out;
    float x;
    float y;
    int i;

    for ( i = 0; i < 100; i++ ) {
        x = ( (float)rand() / (float)RAND_MAX ) * 100.0f;
        y = ( (float)rand() / (float)RAND_MAX ) * 5.0f;
        out = stdlib_base_xlogyf( x, y );
        printf( "xlogyf(%f, %f) = %f\n", x, y, out );
    }
}