Add active parameter support to Python fit functions.

Also add some debug statements to the Fit iteration loop.Refs #970

Code/Mantid/Framework/CurveFitting/src/Fit.cpp

@@ -547,12 +547,16 @@ namespace CurveFitting
     std::string errorString;
     //double costFuncVal = 0;
     //do
+    g_log.debug("Starting minimizer iteration\n");
     while (static_cast<int>(iter) < maxIterations)
     {
       iter++;
+      g_log.debug() << "Starting iteration " << iter << "\n";
       if ( !minimizer->iterate() )
       {
         errorString = minimizer->getError();
+        g_log.debug() << "Iteration stopped. Minimizer status string=" << errorString << "\n";
+
         success = errorString.empty() || errorString == "success";
         if (success)
         {
@@ -562,7 +566,7 @@ namespace CurveFitting
       }
       prog.report();
     }
-
+    g_log.information() << "Number of minimizer iterations=" << iter << "\n";
 
     if (static_cast<int>(iter) >= maxIterations)
     {

Code/Mantid/Framework/PythonInterface/inc/MantidPythonInterface/api/FitFunctions/IFunctionAdapter.h

@@ -87,6 +87,11 @@ namespace Mantid
         this->declareFitParameter(name,0.0,"");
       }
 
+      ///  Override this method to make fitted parameters different from the declared
+      double activeParameter(size_t i)const;
+      /// Override this method to make fitted parameters different from the declared
+      void setActiveParameter(size_t i, double value);
+
     protected:
       /**
        * Returns the PyObject that owns this wrapper, i.e. self

Code/Mantid/Framework/PythonInterface/mantid/api/src/FitFunctions/IFunctionAdapter.cpp

@@ -8,6 +8,8 @@ namespace Mantid
   namespace PythonInterface
   {
     using Mantid::PythonInterface::Environment::CallMethod0;
+    using Mantid::PythonInterface::Environment::CallMethod1;
+    using Mantid::PythonInterface::Environment::CallMethod2;
     using namespace boost::python;
 
     /**
@@ -73,5 +75,37 @@ namespace Mantid
       return result;
     }
 
+    /**
+     * Value of i-th active parameter. If this functions is overridden
+     * in Python then it returns the value of the ith active Parameter
+     * If not it simple returns the base class result
+     * @param i The index of the parameter
+     */
+    double IFunctionAdapter::activeParameter(size_t i) const
+    {
+      return CallMethod1<double,size_t>::dispatchWithDefaultReturn(getSelf(), "activeParameter",
+          this->getParameter(i), i);
+    }
+
+    /**
+     * Sets the value of i-th active parameter. If this functions is overridden
+     * in Python then it should set the value of the ith active parameter
+     * If calls the base class function
+     * @param i The index of the parameter
+     */
+    void IFunctionAdapter::setActiveParameter(size_t i, double value)
+    {
+      try
+      {
+        CallMethod2<void,size_t,double>::dispatchWithException(getSelf(), "setActiveParameter", i,value);
+      }
+      catch(std::runtime_error&)
+      {
+        IFunction::setActiveParameter(i,value);
+      }
+
+    }
+
+
   }
 }