@stdlib/stats-base-dists-t-variance
v0.3.1TypeScript
Student's t distribution variance.
379/weekUpdated 3 days agoApache-2.0Unpacked: 45.9 KB
Published by The Stdlib Authors
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About stdlib...
Variance
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> [Student's t][t-distribution] distribution [variance][variance].
The [variance][variance] for a [Student's t][t-distribution] random variable with degrees of freedom ν is
For ν smaller than one, the variance is not defined.
Installation
``bash`
npm install @stdlib/stats-base-dists-t-variance
Usage
`javascript`
var variance = require( '@stdlib/stats-base-dists-t-variance' );
#### variance( v )
Returns the [variance][variance] of a [Student's t][t-distribution] distribution with degrees of freedom v.
`javascript
var y = variance( 9.0 );
// returns ~1.286
y = variance( 3.5 );
// returns ~2.333
`
If provided 1 < v <= 2, the function returns infinity.
`javascript
var y = variance( 1.5 );
// returns Infinity
y = variance( 2.0 );
// returns Infinity
`
If provided v <= 1, the function returns NaN.
`javascript
var y = variance( -1.0 );
// returns NaN
y = variance( 0.8 );
// returns NaN
`
Examples
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var variance = require( '@stdlib/stats-base-dists-t-variance' );
var opts = {
'dtype': 'float64'
};
var v = uniform( 10, 0.0, 20.0, opts );
logEachMap( 'v: %0.4f, Var(X;v): %0.4f', v, variance );
`
*
C APIs
$3
`c`
#include "stdlib/stats/base/dists/t/variance.h"
#### stdlib_base_dists_t_variance( v )
Returns the variance for a Student's t-distribution.
`c`
double out = stdlib_base_dists_t_variance( 5.0 );
// returns ~1.667
The function accepts the following arguments:
- v: [in] double degrees of freedom.
`c`
double stdlib_base_dists_t_variance( const double v );
$3
`c
#include "stdlib/stats/base/dists/t/variance.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 v;
double y;
int i;
for ( i = 0; i < 25; i++ ) {
v = random_uniform( 2.1, 100.0 );
y = stdlib_base_dists_t_variance( v );
printf( "v: %.4f, Var(X;v): %.4f\n", v, 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-t-variance/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-base-dists-t-variance/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-base-dists-t-variance/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-base-dists-t-variance/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-base-dists-t-variance/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-base-dists-t-variance/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-base-dists-t-variance/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-base-dists-t-variance/main/LICENSE
[t-distribution]: https://en.wikipedia.org/wiki/Student%27s_t-distribution
[variance]: https://en.wikipedia.org/wiki/Variance