class RubyMarkovify::Chain
Public Class Methods
new(corpus, state_size, model = nil)
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# File lib/ruby_markovify/chain.rb, line 8 def initialize(corpus, state_size, model = nil) @state_size = state_size @model = model || build(corpus, @state_size) end
Public Instance Methods
build(corpus, state_size)
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# File lib/ruby_markovify/chain.rb, line 13 def build(corpus, state_size) fail ArgumentError, '`corpus` must be an Array of Arrays!' unless corpus.is_a?(Array) && corpus[0].is_a?(Array) model = {} corpus.each do |run| items = [:begin] * state_size + run + [:end] 0.upto(run.length + 1) do |i| state = items[i...i+state_size] follow = items[i+state_size] model[state] ||= {} model[state][follow] ||= 0 model[state][follow] += 1 end end model end
gen(init_state = nil)
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# File lib/ruby_markovify/chain.rb, line 41 def gen(init_state = nil) state = init_state || [:begin] * @state_size result = [] loop do next_word = move(state) break if next_word == :end result << next_word state = state[1..-1] + [next_word] end result end
Also aliased as: walk
move(state)
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# File lib/ruby_markovify/chain.rb, line 34 def move(state) choices, weights = @model[state].keys, @model[state].values cumdist = RubyMarkovify.cumulative_sum(weights) r = rand * cumdist[-1] choices[cumdist.index { |e| e >= r }] end