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iterNegaLucasSeq
Create an iterator which generates a negaLucas sequence.
The negaLucas numbers are the integer sequence
-->The sequence is defined by the recurrence relation
which yields
with seed values L_0 = 2
and L_{-1} = -1
.
Installation
npm install @stdlib/math-iter-sequences-negalucas
Usage
var iterNegaLucasSeq = require( '@stdlib/math-iter-sequences-negalucas' );
iterNegaLucasSeq( [options] )
Returns an iterator which generates a negaLucas sequence.
var it = iterNegaLucasSeq();
// returns <Object>
var v = it.next().value;
// returns 2
v = it.next().value;
// returns -1
v = it.next().value;
// returns 3
// ...
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 adone
property having aboolean
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:
77
.
The returned iterator can only generate the first 77
negaLucas numbers, as larger negaLucas numbers cannot be safely represented in double-precision floating-point format. By default, the function returns an iterator which generates all 77
numbers. To limit the number of iterations, set the iter
option.
var opts = {
'iter': 2
};
var it = iterNegaLucasSeq( opts );
// returns <Object>
var v = it.next().value;
// returns 2
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 iterNegaLucasSeq = require( '@stdlib/math-iter-sequences-negalucas' );
// Create an iterator:
var it = iterNegaLucasSeq();
// Perform manual iteration...
var v;
while ( true ) {
v = it.next();
if ( v.done ) {
break;
}
console.log( v.value );
}
See Also
-
@stdlib/math-base/special/negalucas
: compute the nth negaLucas 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.
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.