Neural Processing Mechanisms

    @stdlib/iter-step
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    0.0.7 • Public • Published

    iterStep

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    Create an iterator which returns a sequence of numbers according to a specified increment.

    Installation

    npm install @stdlib/iter-step

    Usage

    var iterStep = require( '@stdlib/iter-step' );

    iterStep( start, increment[, N] )

    Returns an iterator which returns a sequence of numbers according to a specified increment.

    var it = iterStep( 0, 2 );
    // returns <Object>
    
    var v = it.next().value;
    // returns 0
    
    v = it.next().value;
    // returns 2
    
    v = it.next().value;
    // returns 4
    
    // ...

    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.

    By default, the function returns an infinite iterator (i.e., an iterator which never ends). To limit the number of returned values, provide a third argument.

    var it = iterStep( 0, 2, 3 );
    // returns <Object>
    
    var v = it.next().value;
    // returns 0
    
    v = it.next().value;
    // returns 2
    
    v = it.next().value;
    // returns 4
    
    var bool = it.next().done;
    // returns true

    Notes

    • The returned iterator is guaranteed to return the start value. Beware, however, that values subsequent to the start value are subject to floating-point rounding errors. For example,

      var it = iterStep( 0.1, 0.2 );
      // returns <Object>
      
      var v = it.next().value;
      // returns 0.1
      
      v = it.next().value;
      // returns ~0.3
      
      v = it.next().value;
      // returns 0.5

      If you desire more control over value precision, consider using roundn:

      var roundn = require( '@stdlib/math-base-special-roundn' );
      var iterMap = require( '@stdlib/iter-map' );
      
      function round( v ) {
          return roundn( v, -2 );
      }
      
      // Create an iterator returning values subject to floating-point errors:
      var it1 = iterStep( 0.1, 0.2, 10 );
      
      // Create an iterator to round each value to the nearest hundredth:
      var it2 = iterMap( it1, roundn );
      
      // Perform manual iteration...
      var v;
      while ( true ) {
          v = it2.next();
          if ( v.done ) {
              break;
          }
          console.log( v.value );
      }
    • If an environment supports Symbol.iterator, the returned iterator is iterable.

    Examples

    var iterStep = require( '@stdlib/iter-step' );
    
    // Create an iterator which is subject to floating-point rounding errors:
    var it = iterStep( 0.0, 0.02, 50 );
    
    // Perform manual iteration...
    var v;
    while ( true ) {
        v = it.next();
        if ( v.done ) {
            break;
        }
        console.log( v.value );
    }

    See Also


    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.

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    License

    See LICENSE.

    Copyright

    Copyright © 2016-2022. The Stdlib Authors.

    Install

    npm i @stdlib/iter-step

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    30

    Version

    0.0.7

    License

    Apache-2.0

    Unpacked Size

    44.7 kB

    Total Files

    9

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser