iterTriangularSeq
Create an iterator which generates a sequence of triangular numbers.
The triangular numbers are the integer sequence
starting at the 0th triangular number.
Triangular numbers are given by the following explicit formulas
where the last formula corresponds to a binomial coefficient, representing the number of distinct pairs that can be selected from n+1 items.
Usage
var iterTriangularSeq = require( '@stdlib/math/iter/sequences/triangular' );
iterTriangularSeq( [options] )
Returns an iterator which generates a sequence of triangular numbers.
var it = iterTriangularSeq();
// returns <Object>
var v = it.next().value;
// returns 0
v = it.next().value;
// returns 1
v = it.next().value;
// returns 3
v = it.next().value;
// returns 6
v = it.next().value;
// returns 10
// ...
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
valueproperty and adoneproperty having abooleanvalue 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:
134217727.
By default, the function returns a finite iterator to avoid exceeding the maximum safe double-precision floating-point integer. To adjust the number of iterations, set the iter option.
var opts = {
'iter': 2
};
var it = iterTriangularSeq( 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 iterTriangularSeq = require( '@stdlib/math/iter/sequences/triangular' );
// Create an iterator:
var opts = {
'iter': 100
};
var it = iterTriangularSeq( opts );
// Perform manual iteration...
var v;
while ( true ) {
v = it.next();
if ( v.done ) {
break;
}
console.log( v.value );
}