stream_stats

= StreamStats {}[https://travis-ci.org/kadwanev/stream_stats]

Extract statistics from long streams of data with minimal space usage and guaranteed precision.

== Install

Add to Gemfile or gem install and require

gem 'stream_stats' require 'stream_stats'

== Usage

=== Stream Quantile Processing

Create stream and add values

stream = StreamStats::Stream.new(0.001, [0.50, 0.90])

Parameters:

1. precision level
2. array of quantiles for guaranteed precision

The above example guarantees that the 50% and 90% percentile results are accurate to +/- 0.001.

Populate stream with samples:

(0..20).each do |i| stream << i end

Get stream result whenever desired:

count - count of stream entries quantile - query value at quantile percentile - query value at percentile min - query min value max - query max value mean - query mean stddev - query standard deviation of stream entries sum - query sum of stream entries squared_sum - query squared sum of stream entries

=== Stream Counting

Create counter and add values

counter = StreamStats::Counter.new

Populate counter with samples:

(0..20).each do |i| counter << i end

Get stream result whenever desired:

count - count of stream entries min - query min value max - query max value mean - query mean stddev - query standard deviation of stream entries sum - query sum of stream entries squared_sum - query squared sum of stream entries

=== Credit

Complete credit goes to Armon Dadgar.
Algorithm code copied directly out of statsite