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    @stdlib/iter-incrspace
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    0.0.7 • Public • Published

    iterIncrspace

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    Create an iterator which returns evenly spaced numbers according to a specified increment.

    Installation

    npm install @stdlib/iter-incrspace

    Usage

    var iterIncrspace = require( '@stdlib/iter-incrspace' );

    iterIncrspace( start, stop[, increment] )

    Returns an iterator which returns evenly spaced numbers according to a specified increment.

    var it = iterIncrspace( 0, 100 );
    // returns <Object>
    
    var v = it.next().value;
    // returns 0
    
    v = it.next().value;
    // returns 1
    
    v = it.next().value;
    // returns 2
    
    // ...

    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 iterator returns values incremented by 1. To adjust value spacing, provide an increment argument.

    var it = iterIncrspace( 0, 5, 2 );
    // 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, but does not include the stop value. Beware, however, that values subsequent to the start value are subject to floating-point rounding errors. For example,

      var it = iterIncrspace( 0.1, 0.9, 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 = iterIncrspace( 0.1, 1.1, 0.2 );
      
      // 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 iterIncrspace = require( '@stdlib/iter-incrspace' );
    
    // Create an iterator which is subject to floating-point rounding errors:
    var it = iterIncrspace( 0.0, 1.01, 0.02 );
    
    // 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-incrspace

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    31

    Version

    0.0.7

    License

    Apache-2.0

    Unpacked Size

    45.1 kB

    Total Files

    9

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser