@toshiara/special-erfinv
v1.0.0
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inverse error function library (commonjs/esm)
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erf / erfc
Inverse error function and inverse complementary error function.
Evaluates the inverse error and inverse complementary error functions.
This package is a rewrite of math-erfinv and math-erfcinv in Typescript. This package supports both CommonJs and ES Modules.
The inverse error function is defined as
\mathrm{erf}^{-1}(z)=\sum_{k=0}^\infty\frac{c_k}{2k+1}\left (\frac{\sqrt{\pi}}{2}z\right )^{2k+1}
where c_0 = 1
and
c_k=\sum_{m=0}^{k-1}\frac{c_m c_{k-1-m}}{(m+1)(2m+1)} = \left\{1,1,\frac{7}{6},\frac{127}{90},\frac{4369}{2520},\frac{34807}{16200},\ldots\right\}
The inverse complementary error function is defined as
\mathrm{erfc}^{-1}(1-z) = \mathrm{erf}^{-1}(z)
Installation
$ npm install @toshiara/special-erfinv
Usage
// for CommonJs
const { erfinv, erfcinv } = require('@toshiara/special-erfinv');
// for ES Modules
import { erfinv, erfcinv } from '@toshiara/special-erfinv';
erf(x)
Evaluates the inverse error function.
erfinv(0.1);
// returns 0.08885599049425769
erfinv(0.4);
// returns 0.37080715859355795
erfinv(0.85);
// returns 1.0179024648320276
erfinv(-1);
// returns -Infinity
erfinv(1);
// returns Infinity
If provided NaN
, the function
returns NaN
.
erfinv(NaN);
// returns NaN
erfinvc(x)
Evaluates the inverse complementary error function.
erfcinv(0.2);
// returns 0.9061938024368231
erfcinv(0.4);
// returns 0.5951160814499948
erfcinv(0.85);
// returns 0.13372692166481973
erfcinv(0);
// returns Infinity
erfcinv(2);
// returns -Infinity
If provided NaN
, the function
returns NaN
.
erfcinv(NaN);
// returns NaN
License
Copyright
Copyright © 2016. The Compute.io Authors.