summary

Takes an array of numbers and calculates some descriptive statistics

#summary

Takes an array of numbers and calculates some descriptive statistics

npm install summary
var summary = require('summary');
 
var data = summary([-1, 0, 1], true /* sorted */);
console.log(data.variance()); // 1 
console.log(data.mean()); // 0 

The summary constructor, takes a required data array and and optional boolean indication whether or not the data is sorted from small to big, by default sorted is false.

// Data is sorted from small to big 
var data = summary([-1, 0, 1], true);
 
// Data is sorted, but summary dosn't know. Works fine just a bit slower. 
var data = summary([-1, 0, 1] /*, default false */);
 
// Data is sorted in reverse order 
var data = summary([1, 0, -1] /*, default false */);
 
// Data isn't sorted 
var data = summary([0, 1, -1] /*, default false */);

The data object has the following metods, note that almost all values is lazy calculated and then cached.

data.sort(); // Returns the sorted array 
 
data.size(); // Returns the data length 
 
data.sum(); // Returns the data sum 
 
data.mode(); // Returns mode 
 
data.mean(); // Returns the mean 
 
data.quartile(0.25); // Returns 25% quartile 
 
data.median(); // Returns the median 
 
data.variance(); // Returns the variance 
 
data.sd(); // Returns the standard deviation 
 
data.max(); // Returns the maximum value 
data.min(); // Returns the minimum value 

##License

The software is license under "MIT"

Copyright (c) 2013 Andreas Madsen

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.