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Compute a sum of products incrementally.
The sum of products is defined as
npm install @stdlib/stats-incr-sumprodAlternatively,
- To load the package in a website via a
scripttag without installation and bundlers, use the ES Module available on theesmbranch (see README). - If you are using Deno, visit the
denobranch (see README for usage intructions). - For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the
umdbranch (see README).
The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.
To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.
var incrsumprod = require( '@stdlib/stats-incr-sumprod' );Returns an accumulator function which incrementally computes a sum of products.
var accumulator = incrsumprod();If provided input values x and y, the accumulator function returns an updated sum. If not provided input value x and y, the accumulator function returns the current sum.
var accumulator = incrsumprod();
var sum = accumulator( 2.0, 3.0 );
// returns 6.0
sum = accumulator( 1.0, -1.0 );
// returns 5.0
sum = accumulator( 3.0, 4.0 );
// returns 17.0
sum = accumulator();
// returns 17.0- Input values are not type checked. If provided
NaNor a value which, when used in computations, results inNaN, the accumulated value isNaNfor 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. - For long running accumulations or accumulations of large numbers, care should be taken to prevent overflow.
var randu = require( '@stdlib/random-base-randu' );
var incrsumprod = require( '@stdlib/stats-incr-sumprod' );
var accumulator;
var v1;
var v2;
var i;
// Initialize an accumulator:
accumulator = incrsumprod();
// For each simulated datum, update the sum-product...
for ( i = 0; i < 100; i++ ) {
v1 = randu() * 100.0;
v2 = randu() * 100.0;
accumulator( v1, v2 );
}
console.log( accumulator() );@stdlib/stats-incr/msumprod: compute a moving sum of products incrementally.@stdlib/stats-incr/prod: compute a product incrementally.@stdlib/stats-incr/sum: compute a sum incrementally.
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.
See LICENSE.
Copyright © 2016-2024. The Stdlib Authors.
