Re #4158. Writing FunctionTest

Code/Mantid/Framework/API/inc/MantidAPI/ParamFunction.h

@@ -91,6 +91,10 @@ class MANTID_API_DLL ParamFunction : public virtual IFunction
 
   /// Number of active (in terms of fitting) parameters
   virtual size_t nActive()const{return m_indexMap.size();}
+  /// Value of i-th active parameter. Override this method to make fitted parameters different from the declared
+  virtual double activeParameter(size_t i)const;
+  /// Set new value of i-th active parameter. Override this method to make fitted parameters different from the declared
+  virtual void setActiveParameter(size_t i, double value);
   /// Returns the name of active parameter i
   virtual std::string nameOfActive(size_t i)const;
   /// Returns the name of active parameter i

Code/Mantid/Framework/API/src/IFunction1D.cpp

@@ -33,17 +33,6 @@ namespace API
 
   Kernel::Logger& IFunction1D::g_log = Kernel::Logger::get("IFunction1D");
 
-/** Base class implementation of derivative IFunction1D throws error. This is to check if such a function is provided
-    by derivative class. In the derived classes this method must return the derivatives of the resuduals function
-    (defined in void Fit1D::function(const double*, double*, const double*, const double*, const double*, const int&))
-    with respect to the fit parameters. If this method is not reimplemented the derivative free simplex minimization
-    algorithm is used.
- */
-void IFunction1D::functionDeriv1D(Jacobian*, const double*, const size_t)
-{
-  throw Kernel::Exception::NotImplementedError("No derivative IFunction1D provided");
-}
-
 namespace
 {
   /**
@@ -91,6 +80,17 @@ void IFunction1D::functionDeriv(const FunctionDomain& domain, Jacobian& jacobian
   functionDeriv1D(&jacobian,(*d1d)[0],d1d->size());
 }
 
+/** Base class implementation of derivative IFunction1D throws error. This is to check if such a function is provided
+    by derivative class. In the derived classes this method must return the derivatives of the resuduals function
+    (defined in void Fit1D::function(const double*, double*, const double*, const double*, const double*, const int&))
+    with respect to the fit parameters. If this method is not reimplemented the derivative free simplex minimization
+    algorithm is used.
+ */
+void IFunction1D::functionDeriv1D(Jacobian*, const double*, const size_t)
+{
+  throw Kernel::Exception::NotImplementedError("No derivative IFunction1D provided");
+}
+
 /** 
  * Creates a workspace containing values calculated with this function. It takes a workspace and ws index
  * of a spectrum which this function may have been fitted to. The output contains the original spectrum 

Code/Mantid/Framework/API/src/ParamFunction.cpp

@@ -230,6 +230,26 @@ void ParamFunction::declareParameter(const std::string& name,double initValue, c
   m_explicitlySet.push_back(false);
 }
 
+/**
+ * Returns the value of an active parameter.
+ * @param i :: The index of an active parameter
+ * @return the value of the active parameter
+ */
+double ParamFunction::activeParameter(size_t i)const
+{
+  return m_parameters[indexOfActive(i)];
+}
+
+/**
+ * Sets the value of an active parameter.
+ * @param i :: The index of an active parameter
+ * @param value :: A new value.
+ */
+void ParamFunction::setActiveParameter(size_t i, double value)
+{
+  m_parameters[indexOfActive(i)] = value;
+}
+
 /**
  * Returns the name of an active parameter.
  * @param i :: The index of an active parameter
@@ -247,7 +267,7 @@ std::string ParamFunction::nameOfActive(size_t i)const
  */
 std::string ParamFunction::descriptionOfActive(size_t i)const
 {
-  return m_parameterDescriptions[indexOfActive(static_cast<int>(i))];
+  return m_parameterDescriptions[indexOfActive(i)];
 }
 
 /**