lib/financial_maths.rb in financial_maths-0.0.5 vs lib/financial_maths.rb in financial_maths-0.0.6

@@ -104,37 +104,54 @@
   # hallar futuro dado la anualidad          HFDA
   def future_given_annuity(annuity, interest, term)
     (annuity * (((1 + interest.to_f) ** term) -1) / interest.to_f ).round(4)
   end
 
-  # hallar tasa efectiva dado la tasa nominal vencida  NVEF
-  def efective_given_nominal_due(nominal_rate, term)
-    (((1 + nominal_rate.to_f) ** term)-1).round(4)
-  end
-
-  # hallar tasa efectiva dado la tasa nominal anticipada    NAEF
-  def efective_given_nominal_antipipated(nominal_rate, term)
-    (1 / ((1 -  nominal_rate.to_f) ** term)).round(4) - 1
-  end
-
-  # hallar tasa nominal anticipada dado efectiva   EFNV
-  def nominal_antipiated_given_efective(nominal_rate, term)
-    (1 - (1 / (1 +  nominal_rate.to_f) ** (1 / term))).round(4)
-  end
-
-  # hallar tasa nominal anticipada dado efectiva   EFNV
-  def nominal_due_given_efective(nominal_rate, term)
-    ((nominal_rate.to_f + 1) ** (1 / term)).round(4)
-  end
+  # == Conversion rates
+  
+    ## 
+    # Description:  Find effective rate given nominal rate expired - NVEF
+    # Formula:      ((1 + (NOMINAL RATE / PERIODS)) ^ PERIODS) - 1
+    def efective_given_nominal_due(nominal_rate, term)
+      ((((1+((nominal_rate.to_f/100)/term))**term)-1).round(6))*100
+    end
+    
+    ##
+    # Description:  Find effective rate given anticipated nominal rate - NAEF
+    # Formula:      ((1 / ((1- (NOMINAL RATE / PERIODS)) ^ PERIODS)) -1
+    def efective_given_nominal_anticipated(nominal_rate, term)
+      (((1/((1-((nominal_rate.to_f/100)/term))**term))-1)*100).round(4)
+    end
+    
+    ##
+    # Description:  Find nominal rate anticipated given effective rate - EFNV
+    # Formulas:      
+    #               nominalRate   = (1 + EFFECTIVE RATE)^(1 / PERIODS) - 1
+    #               toAnticipated =  nominalRate / 1 + nominalRate
+    #               Returned      -> toAnticipated * PERIODS
+    def nominal_anticipated_given_efective(effective_rate, periods)
+      nominalRate = (1+(effective_rate.to_f/100))**(1/periods.to_f)-1;
+      toAnticipated = nominalRate / (1+nominalRate)
+      (toAnticipated * periods.to_f * 100).round(4)     
+    end
+    
+    ##
+    # Description:  Find nominal rate expired given effective rate - EFNV
+    # Formula:      ((1 + EFFECTIVE RATE) ^ (1 / PERIODS) - 1)* PERIODS
+    def nominal_due_given_efective(effective_rate, periods)    
+      ((((1 + (effective_rate.to_f/100))**(1/periods.to_f)-1)*periods.to_f)*100).round(4)    
+    end
+  
+  # == End conversion rates
+  
   # Hallar la cuota fija anticipada   HCFA
   def anticipated_fixed_payment(present_value, rate, term)
     ((present_value.to_f * rate.to_f) / ((rate.to_f + 1) - (1 / (1 + rate) ** (term - 1)))).round(4)
   end
 
   def variable_payment(amount, periods)
     amount.to_f / periods
   end
-
 
 end