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# normalize-range
Utility for normalizing a numeric range, with a wrapping function useful for polar coordinates.
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[![NPM](https://nodei.co/npm/normalize-range.png)](https://nodei.co/npm/normalize-range/)
## Usage
```js var nr = require('normalize-range');
nr.wrap(0, 360, 400); //=> 40
nr.wrap(0, 360, -90); //=> 270
nr.limit(0, 100, 500); //=> 100
nr.limit(0, 100, -20); //=> 0
// There is a convenient currying function var wrapAngle = nr.curry(0, 360).wrap; var limitTo10 = nr.curry(0, 10).limit;
wrapAngle(-30); //=> 330 ``` ## API
### wrap(min, max, value)
Normalizes a values that "wraps around". For example, in a polar coordinate system, 270˚ can also be represented as -90˚. For wrapping purposes we assume `max` is functionally equivalent to `min`, and that `wrap(max + 1) === wrap(min + 1)`. Wrap always assumes that `min` is *inclusive*, and `max` is *exclusive*. In other words, if `value === max` the function will wrap it, and return `min`, but `min` will not be wrapped.
```js nr.wrap(0, 360, 0) === 0; nr.wrap(0, 360, 360) === 0; nr.wrap(0, 360, 361) === 1; nr.wrap(0, 360, -1) === 359; ```
You are not restricted to whole numbers, and ranges can be negative.
```js var π = Math.PI; var radianRange = nr.curry(-π, π);
redianRange.wrap(0) === 0; nr.wrap(π) === -π; nr.wrap(4 * π / 3) === -2 * π / 3; ```
### limit(min, max, value)
Normalize the value by bringing it within the range. If `value` is greater than `max`, `max` will be returned. If `value` is less than `min`, `min` will be returned. Otherwise, `value` is returned unaltered. Both ends of this range are *inclusive*.
### test(min, max, value, [minExclusive], [maxExclusive])
Returns `true` if `value` is within the range, `false` otherwise. It defaults to `inclusive` on both ends of the range, but that can be changed by setting `minExclusive` and/or `maxExclusive` to a truthy value.
### validate(min, max, value, [minExclusive], [maxExclusive])
Returns `value` or throws an error if `value` is outside the specified range.
### name(min, max, value, [minExclusive], [maxExclusive])
Returns a string representing this range in [range notation](https://en.wikipedia.org/wiki/Interval_(mathematics)#Classification_of_intervals).
### curry(min, max, [minExclusive], [maxExclusive])
Convenience method for currying all method arguments except `value`.
```js var angle = require('normalize-range').curry(-180, 180, false, true);
angle.wrap(270) //=> -90
angle.limit(200) //=> 180
angle.test(0) //=> true
angle.validate(300) //=> throws an Error
angle.toString() // or angle.name() //=> "[-180,180)" ```
#### min
*Required* Type: `number`
The minimum value (inclusive) of the range.
#### max
*Required* Type: `number`
The maximum value (exclusive) of the range.
#### value
*Required* Type: `number`
The value to be normalized.
#### returns
Type: `number`
The normalized value.
## Building and Releasing
- `npm test`: tests, linting, coverage and style checks. - `npm run watch`: autotest mode for active development. - `npm run debug`: run tests without coverage (istanbul can obscure line #'s)
Release via `cut-release` tool.
## License
MIT © [James Talmage](http://github.com/jamestalmage)
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