Variance
The variance for a geometric random variable is
where p is the success probability.
Usage
var variance = require( '@stdlib/stats/base/dists/geometric/variance' );
variance( p )
Returns the variance of a geometric distribution with success probability p.
var v = variance( 0.1 );
// returns ~90.0
v = variance( 0.5 );
// returns 2.0
If provided a success probability p outside of [0,1], the function returns NaN.
var v = variance( NaN );
// returns NaN
v = variance( 1.5 );
// returns NaN
v = variance( -1.0 );
// returns NaN
Examples
var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );
var variance = require( '@stdlib/stats/base/dists/geometric/variance' );
var v;
var i;
var p;
for ( i = 0; i < 10; i++ ) {
p = randu();
v = variance( p );
console.log( 'p: %d, Var(X;p): %d', p.toFixed( 4 ), v.toFixed( 4 ) );
}