time-to-botec/squiggle/node_modules/@stdlib/stats/incr/gmean/README.md

incrgmean

Compute a geometric mean incrementally.

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

Usage

var incrgmean = require( '@stdlib/stats/incr/gmean' );

incrgmean()

Returns an accumulator function which incrementally computes a geometric mean.

var accumulator = incrgmean();

accumulator( [x] )

If provided an input value x, the accumulator function returns an updated geometric mean. If not provided an input value x, the accumulator function returns the current geometric mean.

var accumulator = incrgmean();

var prod = accumulator( 2.0 );
// returns 2.0

prod = accumulator( 1.0 );
// returns ~1.414

prod = accumulator( 3.0 );
// returns ~1.817

prod = accumulator();
// returns ~1.817

Notes

• Input values are not type checked. If provided NaN or a value which, when used in computations, results in NaN, the accumulated value is NaN for all future invocations. If non-numeric inputs are possible, you are advised to type check and handle accordingly before passing the value to the accumulator function.

Examples

var randu = require( '@stdlib/random/base/randu' );
var incrgmean = require( '@stdlib/stats/incr/gmean' );

var accumulator;
var v;
var i;

// Initialize an accumulator:
accumulator = incrgmean();

// For each simulated value, update the geometric mean...
for ( i = 0; i < 100; i++ ) {
    v = randu() * 100.0;
    accumulator( v );
}
console.log( accumulator() );