@stdlib/assert-is-triangular-number

Test if a value is a triangular number.


Keywords
stdlib, stdassert, assertion, assert, utilities, utility, utils, util, number, numeric, triangular, triangle, binomial, binomcoef, is, istriangular, type, check, valid, validate, test, primitive, object, javascript, node, node-js, nodejs
License
Apache-2.0
Install
npm install @stdlib/assert-is-triangular-number@0.0.6

Documentation

isTriangularNumber

NPM version Build Status Coverage Status dependencies

Test if a value is a triangular number.

Triangular numbers can be computed using the following formula

Triangular number formula.

for n >= 0.

By analogy with the square root of x, one can define the positive triangular root of x such that T_n = x

Triangular root formula.

Accordingly, an integer x is a triangular number if and only if 8x+1 is a square number.

Installation

npm install @stdlib/assert-is-triangular-number

Usage

var isTriangularNumber = require( '@stdlib/assert-is-triangular-number' );

isTriangularNumber( value )

Tests if a value is a triangular number.

var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber( 36.0 );
// returns true

bool = isTriangularNumber( new Number( 36.0 ) );
// returns true

bool = isTriangularNumber( 3.14 );
// returns false

bool = isTriangularNumber( -5.0 );
// returns false

bool = isTriangularNumber( NaN );
// returns false

bool = isTriangularNumber( null );
// returns false

isTriangularNumber.isPrimitive( value )

Tests if a value is a primitive triangular number.

var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber.isPrimitive( 36.0 );
// returns true

bool = isTriangularNumber.isPrimitive( new Number( 36.0 ) );
// returns false

isTriangularNumber.isObject( value )

Tests if a value is a Number object having a value which is a triangular number.

var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber.isObject( 36.0 );
// returns false

bool = isTriangularNumber.isObject( new Number( 36.0 ) );
// returns true

Notes

  • Return values are not reliable for numbers greater than 1125899906842624.

Examples

var Number = require( '@stdlib/number-ctor' );
var isTriangularNumber = require( '@stdlib/assert-is-triangular-number' );

var bool = isTriangularNumber( 36.0 );
// returns true

bool = isTriangularNumber( new Number( 36.0 ) );
// returns true

bool = isTriangularNumber( 0.0 );
// returns true

bool = isTriangularNumber( 1.0 );
// returns true

bool = isTriangularNumber( 3.14 );
// returns false

bool = isTriangularNumber( -5.0 );
// returns false

bool = isTriangularNumber( NaN );
// returns false

bool = isTriangularNumber( '0.5' );
// returns false

bool = isTriangularNumber( null );
// returns false

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 © 2016-2021. The Stdlib Authors.