time-to-botec/squiggle/node_modules/@stdlib/math/base/special/erfinv

erfinv

Inverse error function.

The inverse error function is defined in terms of the Maclaurin series

where c_0 = 1 and

Usage

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

erfinv( x )

Evaluates the inverse error function.

var y = erfinv( 0.5 );
// returns ~0.4769

y = erfinv( 0.8 );
// returns ~0.9062

y = erfinv( -1.0 );
// returns -Infinity

y = erfinv( 1.0 );
// returns Infinity

The domain of x is restricted to [-1,1]. If |x| > 1, the function returns NaN.

var y = erfinv( -3.14 );
// returns NaN

If provided NaN, the function returns NaN.

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

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

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

Examples

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

var x = linspace( -1.0, 1.0, 100 );
var y;
var i;

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