This is based on Ch. 13 exercises of Think Python adapted to Ruby.

markov.rb uses a markov chain to generate a few paragraphs of text from a source text file.

Some default values are set that can be changed (source text file, number of paragraphs, prefix length (i.e., n in n-gram)).

not_in_list.rb returns the most used words in a file that aren't among the 100 most commonly used words.