Re #11619. Added the new algorithm.

Code/Mantid/Framework/DataHandling/CMakeLists.txt

@@ -7,6 +7,7 @@ set ( SRC_FILES
 	src/CreateModeratorModel.cpp
 	src/CreateSampleShape.cpp
 	src/CreateSimulationWorkspace.cpp
+	src/CropWorkspaceByMask.cpp
 	src/DefineGaugeVolume.cpp
 	src/DeleteTableRows.cpp
 	src/DetermineChunking.cpp
@@ -161,6 +162,7 @@ set ( INC_FILES
 	inc/MantidDataHandling/CreateModeratorModel.h
 	inc/MantidDataHandling/CreateSampleShape.h
 	inc/MantidDataHandling/CreateSimulationWorkspace.h
+	inc/MantidDataHandling/CropWorkspaceByMask.h
 	inc/MantidDataHandling/DefineGaugeVolume.h
 	inc/MantidDataHandling/DeleteTableRows.h
 	inc/MantidDataHandling/DetermineChunking.h
@@ -314,6 +316,7 @@ set ( TEST_FILES
 	CreateModeratorModelTest.h
 	CreateSampleShapeTest.h
 	CreateSimulationWorkspaceTest.h
+	CropWorkspaceByMaskTest.h
 	DefineGaugeVolumeTest.h
 	DeleteTableRowsTest.h
 	DetermineChunkingTest.h

Code/Mantid/Framework/DataHandling/inc/MantidDataHandling/CropWorkspaceByMask.h

@@ -0,0 +1,54 @@
+#ifndef MANTID_DATAHANDLING_CROPWORKSPACEBYMASK_H_
+#define MANTID_DATAHANDLING_CROPWORKSPACEBYMASK_H_
+
+#include "MantidKernel/System.h"
+#include "MantidAPI/Algorithm.h"
+
+namespace Mantid {
+namespace DataHandling {
+
+/** CropWorkspaceByMask crops a MatrixWorkspace by a mask. It removes all masked
+  spectra.
+
+  Copyright © 2015 ISIS Rutherford Appleton Laboratory, NScD Oak Ridge
+  National Laboratory & European Spallation Source
+
+  This file is part of Mantid.
+
+  Mantid is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 3 of the License, or
+  (at your option) any later version.
+
+  Mantid is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+  File change history is stored at: <https://github.com/mantidproject/mantid>
+  Code Documentation is available at: <http://doxygen.mantidproject.org>
+*/
+class DLLExport CropWorkspaceByMask : public API::Algorithm {
+public:
+  CropWorkspaceByMask();
+  virtual ~CropWorkspaceByMask();
+
+  virtual const std::string name() const;
+  virtual int version() const;
+  virtual const std::string category() const;
+  virtual const std::string summary() const;
+
+private:
+  void init();
+  void exec();
+  /// Fill in a vector with spectra indices to be extracted.
+  void makeIndexList(std::vector<size_t>& indices, const API::MatrixWorkspace* maskedWorkspace);
+};
+
+} // namespace DataHandling
+} // namespace Mantid
+
+#endif /* MANTID_DATAHANDLING_CROPWORKSPACEBYMASK_H_ */

Code/Mantid/Framework/DataHandling/src/CropWorkspaceByMask.cpp

@@ -0,0 +1,113 @@
+#include "MantidDataHandling/CropWorkspaceByMask.h"
+#include "MantidDataObjects/MaskWorkspace.h"
+#include "MantidAPI/WorkspaceFactory.h"
+
+namespace Mantid {
+namespace DataHandling {
+
+using namespace Kernel;
+using namespace API;
+
+// Register the algorithm into the AlgorithmFactory
+DECLARE_ALGORITHM(CropWorkspaceByMask)
+
+//----------------------------------------------------------------------------------------------
+/// Constructor
+CropWorkspaceByMask::CropWorkspaceByMask() {}
+
+//----------------------------------------------------------------------------------------------
+/// Destructor
+CropWorkspaceByMask::~CropWorkspaceByMask() {}
+
+//----------------------------------------------------------------------------------------------
+
+/// Algorithms name for identification. @see Algorithm::name
+const std::string CropWorkspaceByMask::name() const {
+  return "CropWorkspaceByMask";
+}
+
+/// Algorithm's version for identification. @see Algorithm::version
+int CropWorkspaceByMask::version() const { return 1; };
+
+/// Algorithm's category for identification. @see Algorithm::category
+const std::string CropWorkspaceByMask::category() const {
+  return "Transforms\\Splitting";
+}
+
+/// Algorithm's summary for use in the GUI and help. @see Algorithm::summary
+const std::string CropWorkspaceByMask::summary() const {
+  return "Extracts unmasked spectra from a workspace and places them in a new "
+         "workspace.";
+}
+
+//----------------------------------------------------------------------------------------------
+/// Initialize the algorithm's properties.
+void CropWorkspaceByMask::init() {
+  declareProperty(
+      new WorkspaceProperty<>("InputWorkspace", "", Direction::Input),
+      "An input workspace.");
+  declareProperty(new WorkspaceProperty<>("MaskedWorkspace", "",
+                                          Direction::Input,
+                                          PropertyMode::Optional),
+                  "If given but not as a MaskWorkspace, the masking from "
+                  "this workspace will be used. If given as a "
+                  "MaskWorkspace, the masking is read from its Y values.");
+  declareProperty(
+      new WorkspaceProperty<>("OutputWorkspace", "", Direction::Output),
+      "An output workspace.");
+}
+
+//----------------------------------------------------------------------------------------------
+/// Execute the algorithm.
+void CropWorkspaceByMask::exec() {
+  MatrixWorkspace_sptr inputWorkspace = getProperty("InputWorkspace");
+  MatrixWorkspace_sptr maskedWorkspace = getProperty("MaskedWorkspace");
+
+  if ( !maskedWorkspace ) maskedWorkspace = inputWorkspace;
+
+  std::vector<size_t> indices;
+  makeIndexList(indices, maskedWorkspace.get());
+
+  // Number of spectra in the cropped workspace.
+  size_t nSpectra = indices.size();
+  // Number of bins/data points in the cropped workspace.
+  size_t nBins = inputWorkspace->blocksize();
+  size_t histogram = inputWorkspace->isHistogramData()? 1 : 0;
+
+  // Create the output workspace
+  MatrixWorkspace_sptr outputWorkspace = WorkspaceFactory::Instance().create(
+      inputWorkspace, nSpectra, nBins, nBins - histogram);
+
+}
+
+//----------------------------------------------------------------------------------------------
+/// Fill in a vector with spectra indices to be extracted.
+/// @param indices :: A reference to a vector to fill with the indices.
+/// @param maskedWorkspace :: A workspace with masking information.
+void CropWorkspaceByMask::makeIndexList(
+    std::vector<size_t> &indices, const API::MatrixWorkspace *maskedWorkspace) {
+  auto mask = dynamic_cast<const DataObjects::MaskWorkspace *>(maskedWorkspace);
+  if (mask) {
+    for (size_t i = 0; i < mask->getNumberHistograms(); ++i) {
+      if (mask->readY(i)[0] == 0.0) {
+        indices.push_back(i);
+      }
+    }
+  } else {
+    for (size_t i = 0; i < maskedWorkspace->getNumberHistograms(); ++i) {
+      Geometry::IDetector_const_sptr det;
+      try {
+        det = maskedWorkspace->getDetector(i);
+      } catch (Exception::NotFoundError &) {
+        continue;
+      }
+
+      if (det->isMasked()) {
+        indices.push_back(i);
+      }
+    }
+  }
+}
+
+} // namespace DataHandling
+} // namespace Mantid

Code/Mantid/Framework/DataHandling/test/CropWorkspaceByMaskTest.h

@@ -0,0 +1,61 @@
+#ifndef MANTID_DATAHANDLING_CROPWORKSPACEBYMASKTEST_H_
+#define MANTID_DATAHANDLING_CROPWORKSPACEBYMASKTEST_H_
+
+#include <cxxtest/TestSuite.h>
+
+#include "MantidDataHandling/CropWorkspaceByMask.h"
+
+using Mantid::DataHandling::CropWorkspaceByMask;
+using namespace Mantid::API;
+
+class CropWorkspaceByMaskTest : public CxxTest::TestSuite
+{
+public:
+  // This pair of boilerplate methods prevent the suite being created statically
+  // This means the constructor isn't called when running other tests
+  static CropWorkspaceByMaskTest *createSuite() { return new CropWorkspaceByMaskTest(); }
+  static void destroySuite( CropWorkspaceByMaskTest *suite ) { delete suite; }
+
+
+  void test_Init()
+  {
+    CropWorkspaceByMask alg;
+    TS_ASSERT_THROWS_NOTHING( alg.initialize() )
+    TS_ASSERT( alg.isInitialized() )
+  }
+
+  void test_exec()
+  {
+    // Name of the output workspace.
+    std::string outWSName("CropWorkspaceByMaskTest_OutputWS");
+
+    CropWorkspaceByMask alg;
+    TS_ASSERT_THROWS_NOTHING( alg.initialize() )
+    TS_ASSERT( alg.isInitialized() )
+    TS_ASSERT_THROWS_NOTHING( alg.setPropertyValue("REPLACE_PROPERTY_NAME_HERE!!!!", "value") );
+    TS_ASSERT_THROWS_NOTHING( alg.setPropertyValue("OutputWorkspace", outWSName) );
+    TS_ASSERT_THROWS_NOTHING( alg.execute(); );
+    TS_ASSERT( alg.isExecuted() );
+
+    // Retrieve the workspace from data service. TODO: Change to your desired type
+    Workspace_sptr ws;
+    TS_ASSERT_THROWS_NOTHING( ws = AnalysisDataService::Instance().retrieveWS<Workspace>(outWSName) );
+    TS_ASSERT(ws);
+    if (!ws) return;
+
+    // TODO: Check the results
+
+    // Remove workspace from the data service.
+    AnalysisDataService::Instance().remove(outWSName);
+  }
+
+  void test_Something()
+  {
+    TSM_ASSERT( "You forgot to write a test!", 0);
+  }
+
+
+};
+
+
+#endif /* MANTID_DATAHANDLING_CROPWORKSPACEBYMASKTEST_H_ */

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

@@ -0,0 +1,44 @@
+
+.. algorithm::
+
+.. summary::
+
+.. alias::
+
+.. properties::
+
+Description
+-----------
+
+TODO: Enter a full rst-markup description of your algorithm here.
+
+
+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
+
+**Example - CropWorkspaceByMask**
+
+.. testcode:: CropWorkspaceByMaskExample
+
+   # Create a host workspace
+   ws = CreateWorkspace(DataX=range(0,3), DataY=(0,2))
+   or
+   ws = CreateSampleWorkspace()
+
+   wsOut = CropWorkspaceByMask()
+
+   # Print the result
+   print "The output workspace has %i spectra" % wsOut.getNumberHistograms()
+
+Output:
+
+.. testoutput:: CropWorkspaceByMaskExample
+
+  The output workspace has ?? spectra
+
+.. categories::
+