Merge remote-tracking branch 'origin/bugfix/10829_MDNormDirectSC_help'

Code/Mantid/Framework/MDAlgorithms/src/MDNormDirectSC.cpp

@@ -448,9 +448,9 @@ void MDNormDirectSC::calculateNormalization(
   }
 
   auto *prog = new API::Progress(this, 0.3, 1.0, ndets);
-  // PARALLEL_FOR_NO_WSP_CHECK()
+  PARALLEL_FOR_NO_WSP_CHECK()
   for (int64_t i = 0; i < ndets; i++) {
-    // PARALLEL_START_INTERUPT_REGION
+    PARALLEL_START_INTERUPT_REGION
 
     const auto detID = detIDs[i];
     double theta(0.0), phi(0.0);
@@ -514,17 +514,17 @@ void MDNormDirectSC::calculateNormalization(
       // *PC
       double signal = solid * delta;
 
-      // PARALLEL_CRITICAL(updateMD)
+      PARALLEL_CRITICAL(updateMD)
       {
         signal += m_normWS->getSignalAt(linIndex);
         m_normWS->setSignalAt(linIndex, signal);
       }
     }
     prog->report();
 
-    // PARALLEL_END_INTERUPT_REGION
+    PARALLEL_END_INTERUPT_REGION
   }
-  // PARALLEL_CHECK_INTERUPT_REGION
+  PARALLEL_CHECK_INTERUPT_REGION
 
   delete prog;
 }

Code/Mantid/docs/source/algorithms/MDNormDirectSC-v1.rst

@@ -12,26 +12,80 @@ Description
 
 The algorithm calculates a normalization MD workspace for single crystal direct geometry inelastic experiments. 
 Trajectories of each detector in reciprocal space are calculated, and the flux is integrated between intersections with each
-MDBox.
+MDBox. A brief introduction to the multi-dimensional data normalization can be found :ref:`here <MDNorm>`
+
+.. Note::
+
+    This is an experimental algorithm in Release 3.3. Please check the nightly Mantid build, and the Mantid webpage
+    for better offline help and usage examples.
+
+.. Note::
+
+    If the MDEvent input workspace is generated from an event workspace, the algorithm gives the correct normalization
+    only if the event workspace is cropped and binned to the same energy transfer range. If the workspace is not cropped, 
+    one might have events in places where the normalization is calculated to be 0.
 
 
 Usage
 -----
-..  Try not to use files in your examples,
-    but if you cannot avoid it then the (small) files must be added to
-    autotestdata\UsageData and the following tag unindented
-    .. include:: ../usagedata-note.txt
+
+.. include:: ../usagedata-note.txt
 
 **Example - MDNormDirectSC**
 
 .. testcode:: MDNormDirectSCExample
 
-
+    import mantid
+    import os
+    from mantid.simpleapi import *
+    config['default.facility']="SNS"
+    from numpy import *
+
+    DGS_input_data=Load("CNCS_7860")
+    # Keep events (SofPhiEIsDistribution=False)
+    # Do not normalize by proton charge in DgsReduction
+    DGS_output_data=DgsReduction(
+             SampleInputWorkspace=DGS_input_data,
+             SofPhiEIsDistribution=False,
+             IncidentBeamNormalisation="None",
+             EnergyTransferRange="-1.5,0.01,2.7",
+            )
+    DGS_output_data=DGS_output_data[0]
+    SetGoniometer(DGS_output_data,Axis0="10.,0,1,0,1")
+    SetUB(DGS_output_data, 5.,3.2,7.2)
+    DGS_output_data=CropWorkspace(DGS_output_data,XMin=-1.5,XMax=2.7)
+    MDE=ConvertToMD(DGS_output_data,
+            QDimensions="Q3D",
+            dEAnalysisMode="Direct",
+            Q3DFrames="HKL",
+            QConversionScales="HKL")
+    histoData,histoNorm=MDNormDirectSC(MDE,
+            AlignedDim0="[H,0,0],-0.2,1.6,100",
+            AlignedDim1="DeltaE,-1.5,3.,100",
+            )
+    normalized=histoData/histoNorm  
+    print "The normalization workspace shape is "+str(histoNorm.getSignalArray().shape)
+    print "Out of those elements, "+str(nonzero(histoNorm.getSignalArray())[0].size)+" are nonzero"
 
 .. testoutput:: MDNormDirectSCExample 
 
-
-
-
+    The normalization workspace shape is (100, 100)
+    Out of those elements, 6712 are nonzero    
+
+.. testcleanup:: MDNormDirectSCExample
+
+   DeleteWorkspace(DGS_input_data)
+   DeleteWorkspace(DGS_output_data)
+   DeleteWorkspace(MDE)
+   DeleteWorkspace(histoData)
+   DeleteWorkspace(histoNorm)
+   DeleteWorkspace(normalized)
+
+
+The output would look like:
+
+.. figure:: /images/MDNormDirectSC.png
+   :alt: MDNormDirectSC.png     
+
 .. categories::
 

Code/Mantid/docs/source/concepts/MDNorm.rst

@@ -0,0 +1,23 @@
+.. _MDNorm:
+
+Multi dimensional neutron scattering data normalization
+=======================================================
+
+In any experiment, a measurement consists of a raw quantity of interest and
+a statistical significance of the measurement itself. 
+For neutron diffraction, the differential scattering cross section at some 
+point :math:`\mathbf{Q}` in the reciprocal space, measured with a single
+detector with a solid angle :math:`d \Omega`, is given by:
+
+.. math::
+
+    \frac{d \sigma}{d \Omega}=\frac{N}{\Phi \times d \Omega}
+    
+where :math:`N` is the number of scattered neutrons in a small volume 
+:math:`d \mathbf{Q}` around :math:`\mathbf{Q}`, and :math:`\Phi` is
+the time integrated incident flux that contribute to the scattering in the given
+volume. 
+
+
+
+