@stdlib/iter-logspace NPM

iterLogspace

Create an iterator which returns evenly spaced numbers over a specified interval.

Installation

npm install @stdlib/iter-logspace

Usage

var iterLogspace = require( '@stdlib/iter-logspace' );

iterLogspace( start, stop[, N][, options] )

Returns an iterator which returns evenly spaced numbers on a log scale.

var it = iterLogspace( 0, 10 );
// returns <Object>

var v = it.next().value;
// returns 1

v = it.next().value;
// returns ~1.26

v = it.next().value;
// returns ~1.59

// ...

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.

The function accepts the following options:

base: base of the log space. Default: 10.

By default, the iterator returns 100 values. To return an alternative number of values, provide an N argument.

var it = iterLogspace( 0, 2, 3 );
// returns <Object>

var v = it.next().value;
// returns 1

v = it.next().value;
// returns 10

v = it.next().value;
// returns 100

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

To specify an alternative log base, provide a base option.

var opts = {
    'base': 2
};
var it = iterLogspace( 0, 10, 11, opts );
// returns <Object>

var v = it.next().value;
// returns 1

v = it.next().value;
// returns 2

v = it.next().value;
// returns 4

// ...

Notes

The returned iterator is guaranteed to include the values base^start and base^stop. Beware, however, that exponents between the start and stop are subject to floating-point rounding errors.
If an environment supports Symbol.iterator, the returned iterator is iterable.

Examples

var iterLogspace = require( '@stdlib/iter-logspace' );

// Create a base-2 iterator:
var opts = {
    'base': 2
};
var it = iterLogspace( 0, 16, 17, opts );

// 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.