@stdlib/math-iter-ops-subtract NPM

iterSubtract

$NPM version$ $Build Status$ $Coverage Status$

Create an iterator which performs element-wise subtraction of two or more iterators.

Installation

npm install @stdlib/math-iter-ops-subtract

Usage

var iterSubtract = require( '@stdlib/math-iter-ops-subtract' );

iterSubtract( iter0, ...iterator )

Returns an iterator which performs element-wise subtraction of two or more iterators.

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

var it1 = array2iterator( [ 1.0, 5.0 ] );
var it2 = array2iterator( [ 3.0, 4.0 ] );

var it = iterSubtract( it1, it2 );
// returns <Object>

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

v = it.next().value;
// returns 1.0

var bool = it.next().done;
// returns true

The returned iterator protocol-compliant object has the following properties:

next: function which returns an iterator protocol-compliant object containing the next iterated value (if one exists) assigned to a value property and a done property having a boolean value indicating whether the iterator is finished.
return: function which closes an iterator and returns a single (optional) argument in an iterator protocol-compliant object.

If provided a numeric value as an iterator argument, the value is broadcast as an infinite iterator which always returns the provided value.

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

var arr = array2iterator( [ 1.0, 2.0 ] );

var it = iterSubtract( arr, 4.0 );
// returns <Object>

var v = it.next().value;
// returns -3.0

v = it.next().value;
// returns -2.0

var bool = it.next().done;
// returns true

Notes

If an iterated value is non-numeric (including NaN), the returned iterator returns NaN. If non-numeric iterated values are possible, you are advised to provide an iterator which type checks and handles non-numeric values accordingly.
The length of the returned iterator is equal to the length of the shortest provided iterator. In other words, the returned iterator ends once one of the provided iterators ends.
If an environment supports Symbol.iterator and provided iterators are iterable, the returned iterator is iterable.

Examples

var iterSineWave = require( '@stdlib/simulate-iter-sine-wave' );
var iterSubtract = require( '@stdlib/math-iter-ops-subtract' );

// Create an iterator which generates a sine wave:
var sine1 = iterSineWave({
    'period': 50,
    'offset': 0,
    'iter': 100
});

// Create another iterator which generates a higher frequency sine wave:
var sine2 = iterSineWave({
    'period': 10,
    'offset': 0,
    'iter': 100
});

// Create an iterator which subtracts the two waveforms:
var it = iterSubtract( sine1, sine2 );

// Perform manual iteration...
var v;
while ( true ) {
    v = it.next();
    if ( v.done ) {
        break;
    }
    console.log( v.value );
}

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.