# @stdlib/stats-incr-gmean

0.2.2 • Public • Published

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# incrgmean

Compute a geometric mean incrementally.

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

## Installation

`npm install @stdlib/stats-incr-gmean`

## 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() );```

## 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.

## Package Sidebar

### Install

`npm i @stdlib/stats-incr-gmean`

### Repository

github.com/stdlib-js/stats-incr-gmean

stdlib.io

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0.2.2

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