Rebin the diff workspaces before minus

Refs #10802
mantidproject · Jan 23, 2015 · 9a3ff9e · 9a3ff9e
1 parent 85a6176
commit 9a3ff9e
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Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/Code/Mantid/MantidQt/CustomInterfaces/src/DataComparison.cpp b/Code/Mantid/MantidQt/CustomInterfaces/src/DataComparison.cpp
@@ -452,12 +452,23 @@ void DataComparison::plotDiffWorkspace()
   extractWs2Alg->execute();
   MatrixWorkspace_sptr ws2SpecWs = extractWs2Alg->getProperty("OutputWorkspace");
 
+  // Rebin the second workspace to the first
+  // (needed for identical binning for Minus algorithm)
+  IAlgorithm_sptr rebinAlg = AlgorithmManager::Instance().create("RebinToWorkspace");
+  rebinAlg->setChild(true);
+  rebinAlg->initialize();
+  rebinAlg->setProperty("WorkspaceToRebin", ws2SpecWs);
+  rebinAlg->setProperty("WorkspaceToMatch", ws1SpecWs);
+  rebinAlg->setProperty("OutputWorkspace", "__ws2_spec_rebin");
+  rebinAlg->execute();
+  MatrixWorkspace_sptr rebinnedWs2SpecWs = rebinAlg->getProperty("OutputWorkspace");
+
   // Subtract the two extracted spectra
   IAlgorithm_sptr minusAlg = AlgorithmManager::Instance().create("Minus");
   minusAlg->setChild(true);
   minusAlg->initialize();
   minusAlg->setProperty("LHSWorkspace", ws1SpecWs);
-  minusAlg->setProperty("RHSWorkspace", ws2SpecWs);
+  minusAlg->setProperty("RHSWorkspace", rebinnedWs2SpecWs);
   minusAlg->setProperty("OutputWorkspace", "__diff");
   minusAlg->execute();
   MatrixWorkspace_sptr diffWorkspace = minusAlg->getProperty("OutputWorkspace");

diff --git a/Code/Mantid/docs/source/interfaces/DataComparison.rst b/Code/Mantid/docs/source/interfaces/DataComparison.rst
@@ -14,6 +14,9 @@ The data comparison interface provides a method of comparing the spectra of
 multiple :ref:`MatrixWorkspace <MatrixWorkspace>` (either pre loaded into
 Mantid or loaded via the interface its self) using a preview plot.
 
+Note that data in this plot is not normalised to bin width as it is by default
+in Mantid plot windows.
+
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