quantize-number

Quantize a number


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Quantization is an operation that takes some number and constrains it to a discrete
set of numbers.

For instance, quantizing the value of 3 to the even numbers could yield either
2 or 4. If the value of 4 is desired, then this library calls that a "covering" algorithm.
If the value of 2 is desired, then that is called a "fitting" algorithm.

This library provides a utility to quantize numbers using both types of algorithms.

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Two use cases for quantization are varied, and include:

1. Drag-to-resize user interfaces
2. Infinite scroll algorithms

#### Caveats

This library is generally unsuitable for quantum physics applications, as it
requires that the discrete set of numbers have even spacing between them.

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The easiest way to install this library is through npm.

``sh
npm install quantize-number
`

Then, import or require it into your library.

`js
// ES2015 syntax
import quantizeNumber from 'quantize-number';

// CJS syntax
var quantizeNumber = require('quantize-number');
`

This library exports UMD, so it works in the most popular JavaScript module
environments, including ES2015, CommonJS, AMD, and also browser globals.

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##### quantizeNumber( val, quantum [, options] )

- val: The number to be quantized
- quantum: The gap between the discrete set numbers
- options: There's currently only one option, cover, which accepts a Boolean
value. This determines whether the algorithm is covering or fitting (see below).

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`js
quantizeNumber(9, 3) === 9;

quantizeNumber(10, 4) === 8;
quantizeNumber(10, 4, {
cover: true
}) === 12;

quantizeNumber(-77, 25) === -75;
`

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The idea of covering vs. fitting is important to this library. Consider quantizing
the value of 78 to a quantum of 25. There are two choices: 75 or 100. If you want
the larger of the two choices, 100, then you want cover: true. Otherwise,
you want cover: false.

The same works for the negative numbers, too. If we have -78 and we're quantizing it
against 25 (or -25), then cover: true would return -100, whereas cover: false` would
return -50.