refs #10384 Mainly finished helper and first unit test working

Code/Mantid/Framework/Algorithms/inc/MantidAlgorithms/BackgroundHelper.h

@@ -7,12 +7,13 @@
 
 #include "MantidAPI/DllConfig.h"
 #include "MantidAPI/MatrixWorkspace.h"
+#include <forward_list>
 
 namespace Mantid
 {
 namespace Algorithms
 {
-/** Class helping to remove constant (and possibly non-constant after simple modification) background calculated in TOF units
+/** Class provides removal of constant (and possibly non-constant after simple modification) background calculated in TOF units
     from a matrix workspace, expressed in units, different from TOF.
 
     @date 26/10/2014
@@ -44,7 +45,10 @@ namespace Algorithms
     BackgroundHelper();
     void initialize(const API::MatrixWorkspace_const_sptr &bkgWS,const API::MatrixWorkspace_sptr &sourceWS,int emode);
 
-    void removeBackground(int hist,const MantidVec &XValues,MantidVec &y_data,MantidVec &e_data);
+    void removeBackground(int hist,const MantidVec &XValues,MantidVec &y_data,MantidVec &e_data)const;
+
+    //returns the list of the failing detectors
+    std::forward_list<int> & getFailingSpectrsList()const{return FailingSpectraList;}
   private:
     // pointer to the units conversion class for the working workspace;
     Kernel::Unit_sptr m_WSUnit;
@@ -56,16 +60,24 @@ namespace Algorithms
 
     // if the background workspace is single value workspace
     bool m_singleValueBackground;
-    // the intensity of the background for a given spectra of a background workspace
+    // the intensity of the background for first spectra of a background workspace
     double m_Jack05;
+    // Squared error of the background for first spectra of a background workspace
+    double m_ErrSq;
     // energy conversion mode
     int m_Emode;
     // source-sample distance
     double m_L1;
     // incident for direct or analysis for indirect energy for units conversion
     double m_Efix;
+    // shared pointer to the sample
     Geometry::IComponent_const_sptr m_Sample;
+    // get Ei attached to direct or indirect instrument workspace
+    double getEi(const API::MatrixWorkspace_const_sptr &inputWS)const;
+
 
+    // list of the spectra numbers for which detectors retrieval has been unsuccessful
+    mutable std::forward_list<int> FailingSpectraList;
   };
 
 }

Code/Mantid/Framework/Algorithms/src/BackgroundHelper.cpp

@@ -5,12 +5,16 @@ namespace Mantid
 {
   namespace Algorithms
   {
+
     /// Constructor
     BackgroundHelper::BackgroundHelper():
+      m_WSUnit(),m_bgWs(),m_wkWS(),
       m_singleValueBackground(false),
+      m_Jack05(0),m_ErrSq(0),
       m_Emode(0),
-      m_Efix(0),
-      m_Jack05(0)
+      m_L1(0),m_Efix(0),
+      m_Sample(),
+      FailingSpectraList()
     {};
 
     /** Initialization method: 
@@ -22,6 +26,7 @@ namespace Mantid
     {
       m_bgWs = bkgWS;
       m_wkWS = sourceWS;
+      FailingSpectraList.clear();
 
       std::string bgUnits = bkgWS->getAxis(0)->unit()->unitID();
       if(bgUnits!="TOF")
@@ -44,30 +49,36 @@ namespace Mantid
       m_singleValueBackground = false;
       if(bkgWS->getNumberHistograms()==0)
         m_singleValueBackground = true;
-      const MantidVec& dataY = bkgWS->dataY(0);
       const MantidVec& dataX = bkgWS->dataX(0);
+      const MantidVec& dataY = bkgWS->dataY(0);
+      const MantidVec& dataE = bkgWS->dataE(0);
       m_Jack05 = dataY[0]/(dataX[1]-dataX[0]);
+      m_ErrSq  = dataE[0]*dataE[0]; // needs further clarification
 
 
+      m_Efix = this->getEi(sourceWS);
     }
     /**Method removes background from vectors which represent a histogram data for a single spectra 
     * @param nHist   -- number (workspaceID) of the spectra in the workspace, where background going to be removed
     * @param XValues -- the spectra x-values (presumably not in TOF units)
     * @param y_data  -- the spectra signal
     * @param e_data  -- the spectra errors
     */
-    void BackgroundHelper::removeBackground(int nHist,const MantidVec &XValues,MantidVec &y_data,MantidVec &e_data)
+    void BackgroundHelper::removeBackground(int nHist,const MantidVec &XValues,MantidVec &y_data,MantidVec &e_data)const
     {
-      double Jack05;
+      double Jack05,ErrSq;
       if(m_singleValueBackground)
       {
         Jack05= m_Jack05;
+        ErrSq   = m_ErrSq;
       }
       else
       {
-        const MantidVec& dataY = m_bgWs->dataY(nHist);
         const MantidVec& dataX = m_bgWs->dataX(nHist);
+        const MantidVec& dataY = m_bgWs->dataY(nHist);
+        const MantidVec& dataE = m_bgWs->dataX(nHist);
         Jack05 = dataY[0]/(dataX[1]-dataX[0]);
+        ErrSq  = dataE[0]*dataE[0]; // Needs further clarification
       }
 
       try
@@ -84,18 +95,59 @@ namespace Mantid
           double tof2=m_WSUnit->convertSingleToTOF(XValues[i+1], m_L1, L2,twoTheta, m_Emode, m_Efix, delta);
           double normBkgrnd = (tof1-tof2)*Jack05;
           tof1=tof2;
-          double normErr    = std::sqrt(normBkgrnd);
-          y_data[i-1] -=normBkgrnd;
-          e_data[i-1] +=normErr;
+          y_data[i] -=normBkgrnd;
+          e_data[i]  =std::sqrt((ErrSq+e_data[i]*e_data[i])/2.); // needs further clarification -- Gaussian error summation
         }
 
       }
       catch(...)
       {
-        // no background removal for this detector; How should it be reported?
+        // no background removal for this spectra as it does not have a detector; How should it be reported?
+        FailingSpectraList.push_front(nHist);
       }
 
     }
+    /** Method returns the efixed or Ei value stored in properties of the input workspace.
+     *  Indirect instruments can have eFxed and Direct instruments can have Ei defined as the properties of the workspace. 
+     *
+     *  This method provide guess for efixed for all other kind of instruments. Correct indirect instrument will overwrite 
+     *  this value while wrongly defined or different types of instruments will provide the value of "Ei" property (log value)
+     *  or undefined if "Ei" property is not found.
+     *
+     */
+    double BackgroundHelper::getEi(const API::MatrixWorkspace_const_sptr &inputWS)const
+    { 
+      double Efi = std::numeric_limits<double>::quiet_NaN();
+
+
+      // is Ei on workspace properties? (it can be defined for some reason if detectors do not have one, and then it would exist as Ei)
+      bool EiFound(false);
+      try
+      {
+         Efi =  inputWS->run().getPropertyValueAsType<double>("Ei");
+         EiFound = true;
+      }
+      catch(Kernel::Exception::NotFoundError &)
+      {}
+      // try to get Efixed as property on a workspace, obtained for indirect instrument
+      bool eFixedFound(false);
+      if (!EiFound)
+      {
+        try
+        {
+           Efi  =inputWS->run().getPropertyValueAsType<double>("eFixed");
+           eFixedFound = true;
+        }
+        catch(Kernel::Exception::NotFoundError &)
+        {}
+      }
+
+      //if (!(EiFound||eFixedFound))
+      //  g_log.debug()<<" Ei/eFixed requested but have not been found\n";
+
+      return Efi;
+    }
+
 
   } // end API
 } // end Mantid

Code/Mantid/Framework/Algorithms/test/BackgroundHelperTest.h

@@ -73,13 +73,34 @@ class BackgroundHelperTest : public CxxTest::TestSuite
 
     unitsConv.execute();
 
+    SourceWS =  API::AnalysisDataService::Instance().retrieveWS<API::MatrixWorkspace>("sampleWSdE");
+
 
   }
 
   ~BackgroundHelperTest()
   {
     BgWS.reset();
+    SourceWS.reset();
+  }
+  void testWrongInit()
+  {
+     Algorithms::BackgroundHelper bgRemoval;
+     // create workspace with units of energy transfer
+     auto bkgWS = WorkspaceCreationHelper::createProcessedInelasticWS(std::vector<double>(1,1.), std::vector<double>(1,20.), std::vector<double>(1,10.));
+     TSM_ASSERT_THROWS("Should throw if background workspace is not in TOF units",bgRemoval.initialize(bkgWS,SourceWS,0),std::invalid_argument);
+
+
+     bkgWS = WorkspaceCreationHelper::create2DWorkspaceWithFullInstrument(2, 15);
+     TSM_ASSERT_THROWS("Should throw if background is not 1 or equal to source",bgRemoval.initialize(bkgWS,SourceWS,0),std::invalid_argument);
+
+     auto sourceWS = WorkspaceCreationHelper::Create2DWorkspace(5,10);
+     TSM_ASSERT_THROWS("Should throw if source workspace does not have units",bgRemoval.initialize(BgWS,sourceWS,0),std::invalid_argument);
+
+     sourceWS ->getAxis(0)->setUnit("TOF");
+     TSM_ASSERT_THROWS("Should throw if source workspace does not have proper instrument",bgRemoval.initialize(BgWS,sourceWS,0),std::invalid_argument);
   }
+
 
   void testBackgroundHelper()
   {
@@ -93,7 +114,8 @@ class BackgroundHelperTest : public CxxTest::TestSuite
   }
 
 private:
-  API::MatrixWorkspace_sptr BgWS;    
+  API::MatrixWorkspace_sptr BgWS;   
+  API::MatrixWorkspace_sptr SourceWS;
 
 };
 

Code/Mantid/Framework/Kernel/inc/MantidKernel/Unit.h

@@ -284,9 +284,9 @@ class MANTID_KERNEL_DLL TOF : public Unit
   virtual double singleToTOF(const double x) const;
   virtual double singleFromTOF(const double tof) const;
   virtual Unit * clone() const;
- ///@return -DBL_MAX as ToF convetanble to TOF for in any time range
+ ///@return -DBL_MAX as ToF convertible to TOF for in any time range
   virtual double conversionTOFMin()const;
- ///@return DBL_MAX as ToF convetanble to TOF for in any time range
+ ///@return DBL_MAX as ToF convertible  to TOF for in any time range
   virtual double conversionTOFMax()const;
 };