a reduce function that calculates mean and standard deviation in one pass
I first wrote this module a long long time ago, and i used an object oriented api. Today I needed to serialize a stats output to JSON, and then later parse it, and keep using it. Continuing to use an OO api would mean a bunch of glue code, so I rewrote it as a reduce function.
var stats = require('statistics')
console.log([1,2,3].reduce(stats))
=> {
mean: 2,
stdev: 0.8164965809277263,
count: 3,
sum: 6,
sqsum: 14
}you probably only want to have the mean and stdev, the other fields are necessary for the reduce function however.
sometimes, a mutating reduce is prefured. this eases garbage collection, and allows you to maintain a reference to an updating value.
otherwise the api is the same.
statistics@2 and earlier used an object oriented api, but then I needed to serialize and parse a stats object and keep using it. That was incredibly easy with a reduce function, but would have meant a bunch of ugly glue code with OO.
MIT