@stdlib/stats-iter-cusum NPM

itercusum

Create an iterator which iteratively computes a cumulative sum.

The cumulative sum is defined as

Installation

npm install @stdlib/stats-iter-cusum

Usage

var itercusum = require( '@stdlib/stats-iter-cusum' );

itercusum( iterator )

Returns an iterator which iteratively computes a cumulative sum.

var array2iterator = require( '@stdlib/array-to-iterator' );

var arr = array2iterator( [ 2.0, 1.0, 3.0, -7.0, -5.0 ] );
var it = itercusum( arr );

var s = it.next().value;
// returns 2.0

s = it.next().value;
// returns 3.0

s = it.next().value;
// returns 6.0

s = it.next().value;
// returns -1.0

s = it.next().value;
// returns -6.0

Notes

If an iterated value is non-numeric (including NaN), the function returns NaN for all future iterations. If non-numeric iterated values are possible, you are advised to provide an iterator which type checks and handles non-numeric values accordingly.

Examples

var runif = require( '@stdlib/random-iter-uniform' );
var itercusum = require( '@stdlib/stats-iter-cusum' );

// Create an iterator for generating uniformly distributed pseudorandom numbers:
var rand = runif( -10.0, 10.0, {
    'seed': 1234,
    'iter': 100
});

// Create an iterator for iteratively computing a cumulative sum:
var it = itercusum( rand );

// Perform manual iteration...
var v;
while ( true ) {
    v = it.next();
    if ( typeof v.value === 'number' ) {
        console.log( 'sum: %d', v.value );
    }
    if ( v.done ) {
        break;
    }
}

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.