Quantiles
Computes quantiles for numeric array.
Installation
$ npm install compute-quantiles
For use in the browser, use browserify.
Usage
To use the module,
var quantiles = ;
quantiles( arr, num[, opts] )
Computes q-quantiles for a numeric array
.
var unsorted = 4 2 5 3 ;var q = ;// returns [ 2, 3.5, 5 ]
If the input array
is already sorted in ascending order, set the sorted
options flag to true
.
var sorted = 2 3 4 5 ;var q = ;// returns [ 2, 3.5, 5 ];
Examples
var data = 1000 ;for var i = 0; i < datalength; i++data i = Math*100;console;
To run the example code from the top-level application directory,
$ node ./examples/index.js
Notes
- This function returns the 0th and 100th quantiles; a.k.a., the min and the max. For example, when computing the median,
var data = 11 ;for var i = 0; i < datalength; i++data i = i+1;console;// returns [ 1, 6, 11 ]
the function returns [1,6,11]
, where min = 1
, max = 11
, and median = 6
. Accordingly, you should expect the output to be an array
with length = q + 1
, where q
is the number of quantiles.
- If provided an unsorted input
array
, the function isO( q + N log(N) )
, whereq
is the number of quantiles andN
is the inputarray
length. If the inputarray
is already sorted in ascending order, the function isO( q )
.
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. Athan Reines.