compute-trimean
v1.0.0
Published
Computes the trimean of a numeric array.
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Trimean
Computes the trimean of a numeric array.
The trimean (or Tukey's trimean) is defined as the weighted average of a distribution's median and its two quartiles. The statistic measures a probability distribution's location and is a statistically resistant L-estimator, having a breakdown point of 25%. The statistic combines the robustness of the median, while accounting for a distribution's shape.
Installation
$ npm install compute-trimean
For use in the browser, use browserify.
Usage
To use the module,
var trimean = require( 'compute-trimean' );
trimean( arr[, opts] )
Computes the trimean of a numeric array
.
var unsorted = [ 5, 8, 9, 1, 7, 6, 2 ];
var tri = trimean( unsorted );
// returns 5.5
If the input array
is already sorted
in ascending order, set the sorted
options flag to true
.
var sorted = [ 1, 2, 5, 6, 7, 8, 9 ];
var tri = trimean( sorted, {'sorted': true} );
// returns 5.5
Additional options are the same as for the quantile module and only apply when computing the first and third quartiles.
Examples
var data = new Array( 100 );
for ( var i = 0; i < data.length; i++ ) {
data[ i ] = Math.round( Math.random()*100 );
}
console.log( trimean( data ) );
To run the example code from the top-level application directory,
$ node ./examples/index.js
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
License
Copyright
Copyright © 2014. Rebekah Smith.