@stdlib/math-base-special-erf NPM

erf

$NPM version$ $Build Status$ $Coverage Status$

Error function.

Installation

npm install @stdlib/math-base-special-erf

Usage

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

erf( x )

Evaluates the error function.

var y = erf( 2.0 );
// returns ~0.9953

y = erf( -1.0 );
// returns ~-0.8427

If provided NaN, the function returns NaN.

var y = erf( NaN );
// returns NaN

The error function is an odd function; i.e., erf(-x) = -erf(x). Thus, in accordance with the IEEE 754 standard, if provided -0, the function returns -0.

var y = erf( -0.0 );
// returns -0.0

Examples

var linspace = require( '@stdlib/array-base-linspace' );
var erf = require( '@stdlib/math-base-special-erf' );

var x = linspace( -10.0, 10.0, 100 );

var i;
for ( i = 0; i < x.length; i++ ) {
    console.log( 'x: %d, erf(x): %d', x[ i ], erf( x[ i ] ) );
}

C APIs

Usage

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

stdlib_base_erf( x )

Evaluates the error function.

double out = stdlib_base_erf( 2.0 );
// returns ~0.9953

out = stdlib_base_erf( -1.0 );
// returns ~-0.8427

The function accepts the following arguments:

x: [in] double input value.

double stdlib_base_erf( const double x );

Examples

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

int main( void ) {
    const double x[] = { -10.0, -7.78, -5.56, -3.33, -1.11, 1.11, 3.33, 5.56, 7.78, 10.0 };
    
    double v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_erf( x[ i ] );
        printf( "x: %lf, erf(x): %lf\n", x[ i ], v );
    }
}

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.