lib/dydx.rb in dydx-0.0.9 vs lib/dydx.rb in dydx-0.1.0

@@ -1,29 +1,50 @@
 require 'dydx/helper'
 require 'dydx/algebra'
+require 'dydx/delta'
+require 'dydx/function'
+require 'dydx/integrand'
 
 module Dydx
   include Algebra
-  class Delta
-    attr_accessor :var, :function
-    def initialize(var, function)
-      @var      = var
-      @function = function
-    end
-
-    def /(delta)
-      if var
-        eval("$#{var}").differentiate(delta.var)
-      elsif delta.function
-        delta.function.differentiate(delta.var)
+  # TODO: Refactor
+  %w(f g h).each do |functioner|
+    define_method(functioner) do |*vars|
+      if function = eval("$#{functioner}")
+        raise ArgumentError, "invalid number of values (#{vars.count} for #{function.vars.count})" unless function.vars.count == vars.count
+        return function if function.vars == vars
+        if function.algebra
+          string = function.algebra.to_s
+                     .gsub('cos', 'Math.cos')
+                     .gsub('sin', 'Math.sin')
+                     .gsub('log', 'Math.log')
+                     .gsub('e', 'Math::E')
+                     .gsub('pi', 'Math::Pi')
+          function.vars.each_with_index do |var, i|
+            string.gsub!(var.to_s, vars[i].to_s)
+          end
+          eval(string)
+        else
+          function
+        end
+      else
+        eval("$#{functioner} = Function.new(*vars)")
       end
     end
   end
 
+  def S(function, delta)
+    Integrand.new(function, delta.var)
+  end
+
+  def d
+    Delta.new
+  end
+
   def method_missing(method, *args, &block)
     method_name = method.to_s
-    if method_name =~ /^d.?$/
-      Delta.new(method_name[1] ?  method_name[1].to_sym : nil, args.first)
+    if method_name =~ /^d.$/
+      Delta.new(method_name[1].to_sym, args.first)
     elsif method_name =~ /^[a-z]$/
       method_name.to_sym
     else
       super
     end