@stdlib/math-base-special-erfinv
v0.3.0
Published
Inverse error function.
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erfinv
The inverse error function is defined in terms of the Maclaurin series
where c_0 = 1
and
Installation
npm install @stdlib/math-base-special-erfinv
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-base-linspace' );
var erfinv = require( '@stdlib/math-base-special-erfinv' );
var x = linspace( -1.0, 1.0, 100 );
var i;
for ( i = 0; i < x.length; i++ ) {
console.log( 'x: %d, erfinv(x): %d', x[ i ], erfinv( x[ i ] ) );
}
C APIs
Usage
#include "stdlib/math/base/special/erfinv.h"
stdlib_base_erfinv( x )
Evaluates the inverse error function.
double out = stdlib_base_erfinv( 0.5 );
// returns ~0.4769
out = stdlib_base_erfinv( 0.8 );
// returns ~0.9062
The function accepts the following arguments:
- x:
[in] double
input value.
double stdlib_base_erfinv( const double x );
Examples
#include "stdlib/math/base/special/erfinv.h"
#include <stdlib.h>
#include <stdio.h>
int main() {
const double x[] = { -1.0, -0.78, -0.56, -0.33, -0.11, 0.11, 0.33, 0.56, 0.78, 1.0 };
double v;
int i;
for ( i = 0; i < 10; i++ ) {
v = stdlib_base_erfinv( x[ i ] );
printf( "x: %lf, erfinv(x): %lf\n", x[ i ], v );
}
}
See Also
@stdlib/math-base/special/erf
: error function.@stdlib/math-base/special/erfc
: complementary error function.@stdlib/math-base/special/erfcinv
: inverse complementary error function.
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.
Community
Copyright
Copyright © 2016-2024. The Stdlib Authors.