@stdlib/stats-incr-mmeanabs2
v0.2.3TypeScript
Compute a moving arithmetic mean of squared absolute values incrementally.
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Published by The Stdlib Authors
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incrmmeanabs2
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> Compute a moving [arithmetic mean][arithmetic-mean] of squared absolute values incrementally.
For a window of size W, the [arithmetic mean][arithmetic-mean] of squared absolute values is defined as
Installation
``bash`
npm install @stdlib/stats-incr-mmeanabs2
Usage
`javascript`
var incrmmeanabs2 = require( '@stdlib/stats-incr-mmeanabs2' );
#### incrmmeanabs2( window )
Returns an accumulator function which incrementally computes a moving [arithmetic mean][arithmetic-mean] of squared absolute values. The window parameter defines the number of values over which to compute the moving mean.
`javascript`
var accumulator = incrmmeanabs2( 3 );
#### accumulator( \[x] )
If provided an input value x, the accumulator function returns an updated mean. If not provided an input value x, the accumulator function returns the current mean.
`javascript
var accumulator = incrmmeanabs2( 3 );
var m = accumulator();
// returns null
// Fill the window...
m = accumulator( 2.0 ); // [2.0]
// returns 4.0
m = accumulator( -1.0 ); // [2.0, -1.0]
// returns 2.5
m = accumulator( 3.0 ); // [2.0, -1.0, 3.0]
// returns ~4.67
// Window begins sliding...
m = accumulator( -7.0 ); // [-1.0, 3.0, -7.0]
// returns ~19.67
m = accumulator( -5.0 ); // [3.0, -7.0, -5.0]
// returns ~27.67
m = accumulator();
// returns ~27.67
`
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 at least W-1 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.W
- As values are needed to fill the window buffer, the first W-1 returned values are calculated from smaller sample sizes. Until the window is full, each returned value is calculated from all provided values.
Examples
`javascript
var randu = require( '@stdlib/random-base-randu' );
var incrmmeanabs2 = require( '@stdlib/stats-incr-mmeanabs2' );
var accumulator;
var v;
var i;
// Initialize an accumulator:
accumulator = incrmmeanabs2( 5 );
// For each simulated datum, update the moving mean...
for ( i = 0; i < 100; i++ ) {
v = ( randu()*100.0 ) - 50.0;
accumulator( v );
}
console.log( accumulator() );
`
*
See Also
- [@stdlib/stats-incr/meanabs2][@stdlib/stats/incr/meanabs2]: compute an arithmetic mean of squared absolute values incrementally.
- [@stdlib/stats-incr/mmeanabs][@stdlib/stats/incr/mmeanabs]: compute a moving arithmetic mean of absolute values incrementally.
- [@stdlib/stats-incr/msumabs2][@stdlib/stats/incr/msumabs2]: compute a moving sum of squared absolute values incrementally.
*
Notice
This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].
#### Community
[![Chat][chat-image]][chat-url]
---
License
See [LICENSE][stdlib-license].
Copyright
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/stats-incr-mmeanabs2/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-incr-mmeanabs2/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-incr-mmeanabs2/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-incr-mmeanabs2/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-incr-mmeanabs2/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-incr-mmeanabs2/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-incr-mmeanabs2/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-incr-mmeanabs2/main/LICENSE
[arithmetic-mean]: https://en.wikipedia.org/wiki/Arithmetic_mean
[@stdlib/stats/incr/meanabs2]: https://www.npmjs.com/package/@stdlib/stats-incr-meanabs2
[@stdlib/stats/incr/mmeanabs]: https://www.npmjs.com/package/@stdlib/stats-incr-mmeanabs
[@stdlib/stats/incr/msumabs2]: https://www.npmjs.com/package/@stdlib/stats-incr-msumabs2