The Fibonacci numbers are the integer sequence

The sequence is defined by the recurrence relation

with seed values F_0 = 0 and F_1 = 1.

Installation

npm install @stdlib/math-iter-sequences-fibonacci

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var iterFibonacciSeq = require( '@stdlib/math-iter-sequences-fibonacci' );

iterFibonacciSeq( [options] )

Returns an iterator which generates a Fibonacci sequence.

var it = iterFibonacciSeq();
// returns <Object>

var v = it.next().value;
// returns 0

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

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

// ...

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 supports the following options:

• iter: number of iterations. Default: 79.

The returned iterator can only generate the first 79 Fibonacci numbers, as larger Fibonacci numbers cannot be safely represented in double-precision floating-point format. By default, the function returns an iterator which generates all 79 numbers. To limit the number of iterations, set the iter option.

var opts = {
    'iter': 2
};
var it = iterFibonacciSeq( opts );
// returns <Object>

var v = it.next().value;
// returns 0

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

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

Notes

• If an environment supports Symbol.iterator, the returned iterator is iterable.

Examples

var iterFibonacciSeq = require( '@stdlib/math-iter-sequences-fibonacci' );

// Create an iterator:
var it = iterFibonacciSeq();

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

See Also

• @stdlib/math-base/special/fibonacci: compute the nth Fibonacci number.
• @stdlib/math-iter/sequences/lucas: create an iterator which generates a Lucas sequence.
• @stdlib/math-iter/sequences/negafibonacci: create an iterator which generates a negaFibonacci sequence.
• @stdlib/math-iter/sequences/nonfibonacci: create an iterator which generates a non-Fibonacci integer sequence.

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.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.