@stdlib/stats-base-dists-binomial-stdev
v0.2.2
Published
Binomial distribution standard deviation.
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Standard Deviation
Binomial distribution standard deviation.
The standard deviation for a binomial random variable is
where n
is the number of trials and p
is the success probability.
Installation
npm install @stdlib/stats-base-dists-binomial-stdev
Usage
var stdev = require( '@stdlib/stats-base-dists-binomial-stdev' );
stdev( n, p )
Returns the standard deviation of a binomial distribution with number of trials n
and success probability p
.
var v = stdev( 20, 0.1 );
// returns ~1.342
v = stdev( 50, 0.5 );
// returns ~3.536
If provided NaN
as any argument, the function returns NaN
.
var v = stdev( NaN, 0.5 );
// returns NaN
v = stdev( 20, NaN );
// returns NaN
If provided a number of trials n
which is not a nonnegative integer, the function returns NaN
.
var v = stdev( 1.5, 0.5 );
// returns NaN
v = stdev( -2.0, 0.5 );
// returns NaN
If provided a success probability p
outside of [0,1]
, the function returns NaN
.
var v = stdev( 20, -1.0 );
// returns NaN
v = stdev( 20, 1.5 );
// returns NaN
Examples
var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var stdev = require( '@stdlib/stats-base-dists-binomial-stdev' );
var v;
var i;
var n;
var p;
for ( i = 0; i < 10; i++ ) {
n = round( randu() * 100.0 );
p = randu();
v = stdev( n, p );
console.log( 'n: %d, p: %d, SD(X;n,p): %d', n, p.toFixed( 4 ), v.toFixed( 4 ) );
}
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
License
See LICENSE.
Copyright
Copyright © 2016-2024. The Stdlib Authors.