# compute-iqr

Computes the interquartile range for an array of values.

## Stats

StarsIssuesVersionUpdatedCreatedSize
compute-iqr
1.1.09 years ago9 years ago

Interquartile Range
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Computes the interquartile range (iqr) for an array of values.

## Installation

``\$ npm install compute-iqr``

For use in the browser, use browserify.

## Usage

To use the module,
``var iqr = require( 'compute-iqr' );``

#### iqr( arr, opts )

Computes the interquartile range provided an input `array`.
``````var unsorted = [ 8, 2, 3, 9, 5, 1, 4, 10, 7, 0, 6 ];

var r = iqr( unsorted );
// returns 6``````

If the input `array` is already `sorted` in ascending order, set the `sorted` flag to `true`.
``````var sorted = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];

var r = iqr( sorted, {'sorted': true} );
// returns 6``````

Additional options are the same as for the quantile module.

## Examples

``````var data = new Array( 100 );

for ( var i = 0; i < data.length; i++ ) {
data[ i ] = Math.round( Math.random()*100 );
}

console.log( iqr( data ) );``````

To run the example code from the top-level application directory,
``\$ node ./examples/index.js``

## Notes

If the input `array` is not sorted in ascending order, the function is `O( N log( N ) )`. If the input `array` is sorted, the function is `O(1)`.

## Tests

### Unit

Unit tests use the Mocha test framework with Chai assertions. To run the tests, execute the following command in the top-level application directory:
``\$ make test``

All new feature development should have corresponding unit tests to validate correct functionality.

### Test Coverage

This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:
``\$ make test-cov``

Istanbul creates a `./reports/coverage` directory. To access an HTML version of the report,
``\$ make view-cov``