Provides a method to compute a moving sum incrementally.
$ npm install compute-incrmsumFor use in the browser, use browserify.
var incrmsum = require( 'compute-incrmsum' );Returns an initialized method to compute a moving sum incrementally. window sets the window size, i.e., the number of values over which to compute a moving sum.
var msum = incrmsum( 3 );If provided a value, the method updates and returns the sum of the current window. If not provided a value, the method returns the current sum.
var sum;
// Filling window...
sum = msum( 2 );
// sum is 2
msum( 3 );
// sum is 5
msum( 2 );
// sum is 7
// Window starts sliding...
msum( -2 );
// sum is 3
msum( 9 );
// sum is 9
sum = msum();
// returns 9- If values have not yet been provided to
msum,msumreturnsnull. - The first
W-1returned sums will have less statistical support than subsequent moving sums, asWvalues are needed to fill the window buffer. Until the window is full, the value returned equals the sum of all values provided thus far.
The use case for this module differs from the conventional vector implementation and the stream implementation. Namely, this module decouples the act of updating the moving sum from the act of consuming the moving sum.
var incrmsum = require( 'compute-incrmsum' );
// Initialize a method to calculate the moving sum incrementally:
var msum = incrmsum( 5 ),
sum;
// Simulate some data...
for ( var i = 0; i < 1000; i++ ) {
sum = msum( Math.random()*100 );
console.log( sum );
}
sum = msum();
console.log( sum );To run the example code from the top-level application directory,
$ node ./examples/index.jsUnit tests use the Mocha test framework with Chai assertions. To run the tests, execute the following command in the top-level application directory:
$ make testAll new feature development should have corresponding unit tests to validate correct functionality.
This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:
$ make test-covIstanbul creates a ./reports/coverage directory. To access an HTML version of the report,
$ make view-covCopyright © 2014-2015. The Compute.io Authors.