inv

Compute the multiplicative inverse of a double-precision floating-point number.

The multiplicative inverse (or reciprocal) is defined as

Usage

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

inv( x )

Computes the multiplicative inverse of a double-precision floating-point number x.

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

v = inv( 2.0 );
// returns 0.5

v = inv( 0.0 );
// returns Infinity

v = inv( -0.0 );
// returns -Infinity

v = inv( NaN );
// returns NaN

Examples

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

var x;
var i;

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

C APIs

Usage

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

stdlib_base_inv( x )

Computes the multiplicative inverse of a double-precision floating-point number.

double y = stdlib_base_inv( 2.0 );
// returns 0.5

The function accepts the following arguments:

x: [in] double input value.

double stdlib_base_inv( const double x );

Examples

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

int main( void ) {
    const double x[] = { 3.0, 4.0, 5.0, 12.0 };

    double y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_inv( x[ i ] );
        printf( "inv(%lf) = %lf\n", x[ i ], y );
    }
}