@stdlib/stats-base-dists-beta-stdev
v0.3.1TypeScript
Beta distribution standard deviation.
0/weekUpdated 4 days agoApache-2.0Unpacked: 41.5 KB
Published by The Stdlib Authors
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About stdlib...
Standard Deviation
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> [Beta][beta-distribution] distribution [standard deviation][stdev].
The [standard deviation][stdev] for a [beta][beta-distribution] random variable is
where α > 0 is the first shape parameter and β > 0 is the second shape parameter.
Installation
``bash`
npm install @stdlib/stats-base-dists-beta-stdev
Usage
`javascript`
var stdev = require( '@stdlib/stats-base-dists-beta-stdev' );
#### stdev( alpha, beta )
Returns the [standard deviation][stdev] of a [beta][beta-distribution] distribution with parameters alpha (first shape parameter) and beta (second shape parameter).
`javascript
var v = stdev( 1.0, 1.0 );
// returns ~0.289
v = stdev( 4.0, 12.0 );
// returns ~0.105
v = stdev( 8.0, 2.0 );
// returns ~0.121
`
If provided NaN as any argument, the function returns NaN.
`javascript
var v = stdev( NaN, 2.0 );
// returns NaN
v = stdev( 2.0, NaN );
// returns NaN
`
If provided alpha <= 0, the function returns NaN.
`javascript
var v = stdev( 0.0, 1.0 );
// returns NaN
v = stdev( -1.0, 1.0 );
// returns NaN
`
If provided beta <= 0, the function returns NaN.
`javascript
var v = stdev( 1.0, 0.0 );
// returns NaN
v = stdev( 1.0, -1.0 );
// returns NaN
`
Examples
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var EPS = require( '@stdlib/constants-float64-eps' );
var stdev = require( '@stdlib/stats-base-dists-beta-stdev' );
var opts = {
'dtype': 'float64'
};
var alpha = uniform( 10, EPS, 10.0, opts );
var beta = uniform( 10, EPS, 10.0, opts );
logEachMap( 'α: %0.4f, β: %0.4f, SD(X;α,β): %0.4f', alpha, beta, stdev );
`
*
C APIs
$3
`c`
#include "stdlib/stats/base/dists/beta/stdev.h"
#### stdlib_base_dists_beta_stdev( alpha, beta )
Returns the [standard deviation][stdev] of a [beta][beta-distribution] distribution with parameters alpha (first shape parameter) and beta (second shape parameter).
`c`
double out = stdlib_base_dists_beta_stdev( 1.0, 1.0 );
// returns ~0.289
The function accepts the following arguments:
- alpha: [in] double first shape parameter.[in] double
- beta: second shape parameter.
`c`
double stdlib_base_dists_beta_stdev( const double alpha, const double beta );
$3
`c
#include "stdlib/stats/base/dists/beta/stdev.h"
#include "stdlib/constants/float64/eps.h"
#include
#include
static double random_uniform( const double min, const double max ) {
double v = (double)rand() / ( (double)RAND_MAX + 1.0 );
return min + ( v*(max-min) );
}
int main( void ) {
double alpha;
double beta;
double y;
int i;
for ( i = 0; i < 25; i++ ) {
alpha = random_uniform( STDLIB_CONSTANT_FLOAT64_EPS, 10.0 );
beta = random_uniform( STDLIB_CONSTANT_FLOAT64_EPS, 10.0 );
y = stdlib_base_dists_beta_stdev( alpha, beta );
printf( "α: %lf, β: %lf, SD(X;α,β): %lf\n", alpha, beta, y );
}
}
`
*
Notice
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].
#### Community
[![Chat][chat-image]][chat-url]
---
License
See [LICENSE][stdlib-license].
Copyright
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[stdlib]: https://github.com/stdlib-js/stdlib
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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/stats-base-dists-beta-stdev/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-base-dists-beta-stdev/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-base-dists-beta-stdev/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-base-dists-beta-stdev/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-base-dists-beta-stdev/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-base-dists-beta-stdev/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-base-dists-beta-stdev/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-base-dists-beta-stdev/main/LICENSE
[beta-distribution]: https://en.wikipedia.org/wiki/Beta_distribution
[stdev]: https://en.wikipedia.org/wiki/Standard_deviation