Inverse incomplete beta function.
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> Inverse of the lower [incomplete beta function][incomplete-beta-function].
``bash`
npm install @stdlib/math-base-special-kernel-betaincinv
`javascript`
var kernelBetaincinv = require( '@stdlib/math-base-special-kernel-betaincinv' );
#### kernelBetaincinv( a, b, p, q )
Inverts the lower regularized [incomplete beta function][incomplete-beta-function] at a > 0 and b > 0. Input probabilities p and q must satisfy p = 1 - q. The function returns a two-element array holding the function value y and 1-y.
`javascript
var y = kernelBetaincinv( 3.0, 3.0, 0.2, 0.8 );
// returns [ ~0.327, ~0.673 ]
y = kernelBetaincinv( 3.0, 3.0, 0.4, 0.6 );
// returns [ ~0.446, ~0.554 ]
y = kernelBetaincinv( 1.0, 6.0, 0.4, 0.6 );
// returns [ ~0.082, ~0.918 ]
y = kernelBetaincinv( 1.0, 6.0, 0.8, 0.2 );
// returns [ ~0.235, ~0.765 ]
`
`javascript
var randu = require( '@stdlib/random-base-randu' );
var kernelBetaincinv = require( '@stdlib/math-base-special-kernel-betaincinv' );
var i;
var p;
var a;
var b;
for ( i = 0; i < 100; i++ ) {
p = randu();
a = randu() * 10.0;
b = randu() * 10.0;
console.log( 'p: %d, \t a: %d, \t b: %d, \t f(p,a,b): %d', p.toFixed( 4 ), a.toFixed( 4 ), b.toFixed( 4 ), kernelBetaincinv( a, b, p, 1.0-p )[ 0 ] );
}
`
*
- [@stdlib/math-base/special/betaincinv][@stdlib/math/base/special/betaincinv]: inverse incomplete beta function.
*
This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].
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---
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[incomplete-beta-function]: https://en.wikipedia.org/wiki/Incomplete_beta_function
[@stdlib/math/base/special/betaincinv]: https://www.npmjs.com/package/@stdlib/math-base-special-betaincinv