lib/dydx/algebra/inverse.rb in dydx-0.1.4 vs lib/dydx/algebra/inverse.rb in dydx-0.1.25

@@ -7,37 +7,30 @@
       def initialize(x, operator)
         @x, @operator = x, operator
       end
 
       def to_s
+        # sym = {'*'=>'/', '+'=>'-'}[operator.to_s]
         case operator
-        when :+ then "( - #{x} )"
-        when :* then "( 1 / #{x} )"
+        when :+
+          "( - #{x} )"
+        when :*
+          "( 1 / #{x} )"
         end
       end
 
-      def subst(hash = {})
+      def differentiate(sym=:x)
         case operator
-        when :+ then x.subst(hash) * -1
-        when :* then x.subst(hash) ** -1
-        end
-      end
-
-      def to_f
-        case operator
-        when :+ then x.to_f * -1
-        when :* then x.to_f ** -1
-        end
-      end
-
-      def differentiate(sym = :x)
-        case operator
         when :+
           inverse(x.differentiate(sym), :+)
         when :*
-          inverse(x.differentiate(sym) * inverse(x ** 2, :*), :+)
+          inverse(x.differentiate(sym) * inverse(x ^ 2, :*), :+)
         end
       end
       alias_method :d, :differentiate
+
+      def ==(x)
+        to_s == x.to_s
+      end
     end
   end
-end
+end
\ No newline at end of file