Added option to ignore invalid data in Fit. Re #7182.

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

@@ -59,7 +59,7 @@ namespace Mantid
         const std::vector<std::string>& workspacePropertyNames,
         DomainType domainType = Simple);
       /// Virtual destructor
-      virtual ~IDomainCreator() {};
+      virtual ~IDomainCreator() {}
       /// Initialize
       virtual void initialize(Kernel::IPropertyManager* , const std::string&, DomainType) {}
 
@@ -103,6 +103,9 @@ namespace Mantid
       /// Return the size of the domain to be created.
       virtual size_t getDomainSize() const = 0;
 
+      /// Set to ignore invalid data
+      void ignoreInvalidData( bool yes ) {m_ignoreInvalidData = yes;}
+
     protected:
       /// Declare a property to the algorithm
       void declareProperty(Kernel::Property* prop,const std::string& doc);
@@ -114,6 +117,8 @@ namespace Mantid
       DomainType m_domainType;
       /// Output separate composite function values
       bool m_outputCompositeMembers;
+      /// Flag to ignore nans, infinities and zero errors.
+      bool m_ignoreInvalidData;
     };
 
     /// Typedef for a shared pointer to IDomainCreator.

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

@@ -20,7 +20,7 @@ namespace API
     DomainType domainType):
   m_manager( manager ),
   m_workspacePropertyNames( workspacePropertyNames ),
-  m_domainType( domainType ), m_outputCompositeMembers(false)
+    m_domainType( domainType ), m_outputCompositeMembers( false ), m_ignoreInvalidData( false )
   {}
 
   /**

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

@@ -448,6 +448,7 @@ namespace CurveFitting
     mustBePositive->setLower(0);
     declareProperty("MaxIterations", 500, mustBePositive->clone(),
       "Stop after this number of iterations if a good fit is not found" );
+    declareProperty("IgnoreInvalidData",false,"Flag to ignore infinities, NaNs and data with zero errors.");
     declareProperty("OutputStatus","", Kernel::Direction::Output);
     getPointerToProperty("OutputStatus")->setDocumentation( "Whether the fit was successful" );
     declareProperty("OutputChi2overDoF",0.0, "Returns the goodness of the fit", Kernel::Direction::Output);
@@ -517,6 +518,7 @@ namespace CurveFitting
 
     API::FunctionDomain_sptr domain;
     API::IFunctionValues_sptr values;
+    m_domainCreator->ignoreInvalidData(getProperty("IgnoreInvalidData"));
     m_domainCreator->createDomain(domain,values);
 
     // do something with the function which may depend on workspace

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

@@ -17,6 +17,7 @@
 #include "MantidKernel/BoundedValidator.h"
 #include "MantidKernel/EmptyValues.h"
 
+#include <boost/math/special_functions/fpclassify.hpp>
 #include <algorithm>
 
 namespace Mantid
@@ -244,14 +245,26 @@ namespace
     for(size_t i = m_startIndex; i < ito; ++i)
     {
       size_t j = i - m_startIndex + i0;
-      values->setFitData( j, Y[i] );
+      double y = Y[i];
       double error = E[i];
-      if (error <= 0)
+      double weight = 0.0;
+
+      if ( ! boost::math::isfinite(y) )
+      {
+          if ( !m_ignoreInvalidData ) throw std::runtime_error("Infinte number or NaN found in input data.");
+          y = 0.0; // leaving inf or nan would break the fit
+      }
+      else if ( error <= 0 )
       {
-        error = 1.0;
-        //foundZeroOrNegativeError = true;
+          if ( !m_ignoreInvalidData ) weight = 1.0;
       }
-      values->setFitWeight( j, 1.0 / error );
+      else
+      {
+          weight = 1.0 / error;
+      }
+
+      values->setFitData( j, y );
+      values->setFitWeight( j, weight );
     }
 
   }

Code/Mantid/Framework/CurveFitting/test/FitMWTest.h

@@ -361,6 +361,82 @@ class FitMWTest : public CxxTest::TestSuite
 
   }
 
+  void test_ignore_invalid_data()
+  {
+      auto ws = createTestWorkspace(false);
+      const double zero = 0.0;
+      const double one = 1.0;
+      ws->dataY(0)[3] = 1.0 / zero;
+      ws->dataY(0)[5] = log(-one);
+      ws->dataE(0)[7] = 0;
+
+      FunctionDomain_sptr domain;
+      IFunctionValues_sptr values;
+
+      // Requires a property manager to make a workspce
+      auto propManager = boost::make_shared<Mantid::Kernel::PropertyManager>();
+      const std::string wsPropName = "TestWorkspaceInput";
+      propManager->declareProperty(new WorkspaceProperty<Workspace>(wsPropName, "", Mantid::Kernel::Direction::Input));
+      propManager->setProperty<Workspace_sptr>(wsPropName, ws);
+
+      FitMW fitmw(propManager.get(), wsPropName);
+      fitmw.declareDatasetProperties("", true);
+      fitmw.ignoreInvalidData(true);
+      fitmw.createDomain(domain, values);
+
+      FunctionValues *val = dynamic_cast<FunctionValues*>(values.get());
+      for(size_t i = 0; i < val->size(); ++i)
+      {
+          if ( i == 3 || i == 5 || i == 7 )
+          {
+              TS_ASSERT_EQUALS( val->getFitWeight(i), 0.0 );
+          }
+          else
+          {
+              TS_ASSERT_DIFFERS( val->getFitWeight(i), 0.0 );
+          }
+      }
+
+      API::IFunction_sptr fun(new ExpDecay);
+      fun->setParameter("Height",1.);
+      fun->setParameter("Lifetime",1.0);
+
+      Fit fit;
+      fit.initialize();
+
+      fit.setProperty("Function",fun);
+      fit.setProperty("InputWorkspace",ws);
+      fit.setProperty("WorkspaceIndex",0);
+
+      fit.execute();
+      TS_ASSERT(! fit.isExecuted());
+
+      fit.setProperty("IgnoreInvalidData",true);
+      fit.setProperty("Minimizer","Levenberg-Marquardt");
+      fit.execute();
+      TS_ASSERT(fit.isExecuted());
+
+      TS_ASSERT_DELTA( fun->getParameter("Height"), 10.0, 1e-3);
+      TS_ASSERT_DELTA( fun->getParameter("Lifetime"), 0.5, 1e-4);
+
+      // check Levenberg-MarquardtMD minimizer
+      fun->setParameter("Height",1.);
+      fun->setParameter("Lifetime",1.0);
+      Fit fit1;
+      fit1.initialize();
+      fit1.setProperty("Function",fun);
+      fit1.setProperty("InputWorkspace",ws);
+      fit1.setProperty("WorkspaceIndex",0);
+      fit1.setProperty("IgnoreInvalidData",true);
+      fit1.setProperty("Minimizer","Levenberg-MarquardtMD");
+      fit1.execute();
+      TS_ASSERT(fit1.isExecuted());
+
+      TS_ASSERT_DELTA( fun->getParameter("Height"), 10.0, 1e-3);
+      TS_ASSERT_DELTA( fun->getParameter("Lifetime"), 0.5, 1e-4);
+
+  }
+
 
 private: