Variance

Degenerate distribution variance.

The variance for a degenerate random variable is

where μ is the constant value of the distribution.

Installation

npm install @stdlib/stats-base-dists-degenerate-variance

Usage

var variance = require( '@stdlib/stats-base-dists-degenerate-variance' );

variance( mu )

Returns the variance of a degenerate distribution with constant value mu.

var v = variance( 10.0 );
// returns 0.0

v = variance( -0.5 );
// returns 0.0

v = variance( NaN );
// returns NaN

Examples

var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var variance = require( '@stdlib/stats-base-dists-degenerate-variance' );

var opts = {
    'dtype': 'float64'
};
var mu = uniform( 10, 0.0, 1.0, opts );

logEachMap( 'µ: %0.4f, Var(X;µ): %0.4f', mu, variance );

C APIs

Usage

#include "stdlib/stats/base/dists/degenerate/variance.h"

stdlib_base_dists_degenerate_variance( mu )

Returns the variance of a degenerate distribution.

double out = stdlib_base_dists_degenerate_variance( 0.1 );
// returns 0.0

The function accepts the following arguments:

• mu: [in] double constant value of distribution.

double stdlib_base_dists_degenerate_variance( const double mu );

Examples

#include "stdlib/stats/base/dists/degenerate/variance.h"
#include <stdlib.h>
#include <stdio.h>

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 mu;
    double y;
    int i;

    for ( i = 0; i < 25; i++ ) {
        mu = random_uniform( -50.0, 50.0 );
        y = stdlib_base_dists_degenerate_variance( mu );
        printf( "µ: %lf, Var(X;µ): %lf\n", mu, y );
    }
}

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 © 2016-2026. The Stdlib Authors.