itercugmean

Create an iterator which iteratively computes a cumulative geometric mean.

The geometric mean is defined as the nth root of a product of n numbers.

left-parenthesis product Underscript i equals 0 Overscript n minus 1 Endscripts right-parenthesis Superscript StartFraction 1 Over n EndFraction Baseline equals RootIndex n StartRoot x 0 x 1 midline-horizontal-ellipsis x Subscript n minus 1 Baseline EndRoot

Usage

var itercugmean = require( '@stdlib/stats/iter/cugmean' );

itercugmean( iterator )

Returns an iterator which iteratively computes a cumulative geometric mean.

var array2iterator = require( '@stdlib/array/to-iterator' );

var arr = array2iterator( [ 2.0, 1.0, 3.0, 7.0, 5.0 ] );
var it = itercugmean( arr );

var v = it.next().value;
// returns 2.0

v = it.next().value;
// returns ~1.41

v = it.next().value;
// returns ~1.82

v = it.next().value;
// returns ~2.55

v = it.next().value;
// returns ~2.91

Notes

  • If an iterated value is non-numeric (including NaN) or negative, the function returns NaN for all future iterations. If non-numeric and/or negative iterated values are possible, you are advised to provide an iterator which type checks and handles such values accordingly.

Examples

var runif = require( '@stdlib/random/iter/uniform' );
var itercugmean = require( '@stdlib/stats/iter/cugmean' );

// Create an iterator for generating uniformly distributed pseudorandom numbers:
var rand = runif( 0.0, 10.0, {
    'seed': 1234,
    'iter': 100
});

// Create an iterator for iteratively computing a cumulative geometric mean:
var it = itercugmean( rand );

// Perform manual iteration...
var v;
while ( true ) {
    v = it.next();
    if ( typeof v.value === 'number' ) {
        console.log( 'gmean: %d', v.value );
    }
    if ( v.done ) {
        break;
    }
}