flow-csum

Transform stream factory to calculate the cumulative sum of a numeric data stream.

Installation

$ npm install flow-csum

API

To create a stream factory,

var sumStream = require( 'flow-csum' );
 
// Create a new factory:
var sStream = sumStream();

sStream.sum( [value] )

This method is a setter/getter. If no value is provided, returns the initial sum value. To set the initial sum,

sStream.sum( 100 );

sStream.stream()

To create a new sum stream,

var stream = sStream.stream();

Usage

Methods are chainable,

sumStream()
    .sum( 100 )
    .stream()
    .pipe( /* writable stream */ );

Examples

var eventStream = require( 'event-stream' ),
    sStream = require( 'flow-csum' );
 
// Create some data...
var data = new Array( 1000 );
for ( var i = 0; i < 1000; i++ ) {
    data[ i ] = Math.random();
}
 
// Create a readable stream:
var readStream = eventStream.readArray( data );
 
// Create a new sum stream:
var stream = sStream().stream();
 
// Pipe the data:
readStream.pipe( stream )
    .pipe( eventStream.map( function( d, clbk ) {
        clbk( null, d.toString()+'\n' );
    }))
    .pipe( process.stdout );

Tests

Unit tests use the Mocha test framework with Chai assertions.

Assuming you have installed Mocha, execute the following command in the top-level application directory to run the tests:

$ mocha

All new feature development should have corresponding unit tests to validate correct functionality.

License

MIT license.

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Copyright

Copyright © 2014. Athan Reines.