Skip to content

Latest commit

 

History

History
273 lines (181 loc) · 9.07 KB

README.md

File metadata and controls

273 lines (181 loc) · 9.07 KB
About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

incrmsummary

NPM version Build Status Coverage Status

Compute a moving statistical summary incrementally.

Usage

import incrmsummary from 'https://cdn.jsdelivr.net/gh/stdlib-js/stats-incr-msummary@deno/mod.js';

incrmsummary( window )

Returns an accumulator function which incrementally computes a moving statistical summary. The window parameter defines the number of values over which to compute the moving summary.

var accumulator = incrmsummary( 3 );

accumulator( [x] )

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

var accumulator = incrmsummary( 3 );

var summary = accumulator();
// returns {}

// Fill the window...
summary = accumulator( 2.0 ); // [2.0]
/* returns
    {
        'window': 3,
        'sum': 2.0,
        'mean': 2.0,
        'variance': 0.0,
        'stdev': 0.0,
        'min': 2.0,
        'max': 2.0,
        'range': 0.0,
        'midrange': 2.0
    }
*/

summary = accumulator( 1.0 ); // [2.0, 1.0]
/* returns
    {
        'window': 3,
        'sum': 3.0,
        'mean': 1.5,
        'variance': 0.5,
        'stdev': 0.7071067811865476,
        'min': 1.0,
        'max': 2.0,
        'range': 1.0,
        'midrange': 1.5
    }
*/

summary = accumulator( -3.0 ); // [2.0, 1.0, -3.0]
/* returns
    {
        'window': 3,
        'sum': 0.0,
        'mean': 0.0,
        'variance': 7.0,
        'stdev': 2.6457513110645907,
        'min': -3.0,
        'max': 2.0,
        'range': 5.0,
        'midrange': -0.5
    }
*/

// Window begins sliding...
summary = accumulator( -7.0 ); // [1.0, -3.0, -7.0]
// returns {...}

summary = accumulator( -5.0 ); // [-3.0, -7.0, -5.0]
// returns {...}

summary = accumulator();
// returns {...}

Notes

  • Input values are not type checked. If non-numeric inputs are possible, you are advised to type check and handle accordingly before passing the value to the accumulator function.
  • As W values are needed to fill the window buffer, the first W-1 returned summaries are calculated from smaller sample sizes. Until the window is full, each returned summary is calculated from all provided values.

Examples

import randu from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-randu@deno/mod.js';
import incrmsummary from 'https://cdn.jsdelivr.net/gh/stdlib-js/stats-incr-msummary@deno/mod.js';

var accumulator;
var v;
var i;

// Initialize an accumulator:
accumulator = incrmsummary( 5 );

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

See Also


Notice

This package is part of stdlib, a standard library 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.

Community

Chat


License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.