datasets-anscombes-quartet
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Anscombe's quartet.
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Anscombe's Quartet
Anscombe's quartet is a set of 4
datasets which all have nearly identical simple statistical properties but vary considerably when graphed. Anscombe created the datasets to demonstrate why graphical data exploration should precede statistical data analysis and to show the effect of outliers on statistical properties.
Installation
$ npm install datasets-anscombes-quartet
Usage
var data = require( 'datasets-anscombes-quartet' );
data
Anscombe's quartet comprises 4
individual datasets, where each individual dataset is an array
of [x,y]
tuples.
console.log( data );
/*
[
[
[10,8.04],
[8,6.95],
...
],
[
[10,9.14],
[8,8.14],
...
],
...
]
*/
Examples
var toMatrix = require( 'compute-to-matrix' ),
mean = require( 'compute-mean' ),
variance = require( 'compute-variance' ),
data = require( 'datasets-anscombes-quartet' );
var len = data.length,
mats = new Array( len ),
mu,
s2,
i;
// Convert the individual datasets to matrices...
for ( i = 0; i < len; i++ ) {
mats[ i ] = toMatrix( data[ i ] );
}
/*
[ xi0 yi0
xi1 yi1
xi2 yi2
mats[ i ] = .
.
.
xiN yiN ]
*/
// Calculate the means and variances along the rows for each matrix...
for ( i = 0; i < len; i++ ) {
mu = mean( mats[ i ], {
'dim': 1
});
/*
[ E[x], E[y] ]
*/
s2 = variance( mats[ i ], {
'dim': 1
});
/*
[ Var[x], Var[y] ]
*/
console.log( 'Dataset %d: E[x] = %d, Var[x] = %d.', i+1, mu.get(0,0), s2.get(0,0) );
console.log( 'Dataset %d: E[y] = %d, Var[y] = %d.\n', i+1, mu.get(0,1), s2.get(0,1) );
}
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 © 2015. The Compute.io Authors.