lutzky · July 23, 2008 05:02
diff --git a/derivative.rb b/derivative.rb
 Epsilon = 1e-10

 def d_dx(&f) # :yields: x
  Proc.new do |x|
    (f[x + Epsilon] - f[x])/Epsilon
  end
 end
    
diff --git a/example.rb b/example.rb
 require 'derivative'

 if __FILE__ == $0
  puts "Derivation example: g is the derivative of x**2"
  g = d_dx { |x| x**2 }
  puts "g[8] is #{g[8]}"
 end
	require 'derivative'

	if __FILE__ == $0
	puts "Derivation example: g is the derivative of x**2"
	g = d_dx { \|x\| x**2 }
	puts "g[8] is #{g[8]}"
	end