began writing code for recommendation engine based on similarity scores to find other users similar to current user
1) created scoring.rb file for this which includes two things
a) creating a dictionary of all users and their beer ratings
b) pearson similarity score based on 'programming collective intelligence' by toby segaran
added method to find unrated beers
added method to calculated expected values of unrated beers based on a single other user
fixed simpearson calculation
pearson similarity calculations
1) simpearson calculation was resulting in a denominator of 0 for two users with no mutually rated beers. fixed so that method returns 0 if there are no mutually rated beers (as opposed to "NaN" which was getting returned before)
2) top_matches method which returns the top 10 highest pearson similarity scores and user id's
JSON and ActiveRecord
1) added the score related methods to a module Score in models
2) create migration for pg JSON dictionary data
wrote populate.rake file in lib/tasks to populate dictionary db table with most recent rating data
Score module self methods to calculate pearson similarity score and other statistics
created functionality to see which other users have the top similarity scores as user
1) some variables needed to be cast as strings to match up with dictionary JSON
2) users view updated for top 10 users
updated readme
Merge pull request #23 from vikram7/vr-find-similar-users

began writing code for recommendation engine based on similarity scores ...