Class: Array

Inherits:
Object
  • Object
show all
Defined in:
lib/mod_array.rb

Instance Method Summary collapse

Instance Method Details

#random(array = nil) ⇒ Object 



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# File 'lib/mod_array.rb', line 2

def random array = nil
	if array
		raise ArgumentError, "weight array must match length of array (#{length})" unless length == array.length
		max_weight = 0
		array.each {|n| max_weight += n }
		target_weight = rand max_weight
		index = 0
		index_weight = array[index]
		while index_weight <= target_weight
			index += 1
			index_weight += array[index]
		end
		self[index]
	else
		self[rand length]
	end
end