Module: GPTreeHelper

Extended by:
GPTreeHelper
Included in:
GPTreeHelper
Defined in:
lib/charlie/tree/tree.rb

Overview

some general helper functions, which are independant of the operator arrays

Instance Method Summary collapse

Instance Method Details

#all_subtrees(t = @genes) ⇒ Object 



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# File 'lib/charlie/tree/tree.rb', line 29

def all_subtrees(t=@genes)
  if t.first==:term
    [t]
  else
    t[1..-1].map{|st| all_subtrees(st) }.inject{|a,b|a+b} << t
  end
end

#all_terminals(t = @genes) ⇒ Object 



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# File 'lib/charlie/tree/tree.rb', line 41

def all_terminals(t=@genes)
  if t.first==:term
    [t]
  else
    t[1..-1].map{|st| all_terminals(st) }.inject{|a,b|a+b}
  end
end

#dup_tree(t) ⇒ Object 



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# File 'lib/charlie/tree/tree.rb', line 5

def dup_tree(t)
  if t.first==:term
    t.clone # avoid inf recursion here
  else
    t.map{|st| st.is_a?(Symbol) ? st : dup_tree(st) }
  end
end

#eval_tree(tree, values_hash) ⇒ Object 



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# File 'lib/charlie/tree/tree.rb', line 53

def eval_tree(tree,values_hash)
  if tree.first == :term
    termval = tree[1]
    if termval.is_a?(Symbol) # look up symbols in the hash
      termval = values_hash[termval]
      termval = termval.call if termval.is_a?(Proc) # and if hash value is a proc, evaluate it
    end
    termval
  else # tree.first is an operator
    eval_tree(tree[1],values_hash).send(tree.first, *tree[2..-1].map{|t| eval_tree(t,values_hash) } )
  end
end

#random_subtree(t = @genes) ⇒ Object 



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# File 'lib/charlie/tree/tree.rb', line 37

def random_subtree(t=@genes)
  all_subtrees(t).at_rand
end

#random_terminal(t = @genes) ⇒ Object 



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# File 'lib/charlie/tree/tree.rb', line 49

def random_terminal(t=@genes)
  all_terminals(t).at_rand
end

#tree_depth(t) ⇒ Object 



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# File 'lib/charlie/tree/tree.rb', line 21

def tree_depth(t)
  if t.first==:term
    0
  else
    1 + t[1..-1].map{|st| tree_depth(st) }.max
  end
end

#tree_size(t) ⇒ Object 



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# File 'lib/charlie/tree/tree.rb', line 13

def tree_size(t)
  if t.first==:term
    1
  else
    t[1..-1].inject(1){|sum,st| sum + tree_size(st) }
  end
end