Refs #10774. Added PoldiSpectrumConstantBackground

This function inherits from FlatBackground and implements IPoldiFunction1D.

Code/Mantid/Framework/SINQ/CMakeLists.txt

@@ -35,6 +35,7 @@ set ( SRC_FILES
 	src/PoldiUtilities/PoldiResidualCorrelationCore.cpp
         src/PoldiUtilities/PoldiSpectrumDomainFunction.cpp
         src/PoldiUtilities/PoldiSourceSpectrum.cpp
+	src/PoldiUtilities/PoldiSpectrumConstantBackground.cpp
 	src/PoldiUtilities/PoldiSpectrumLinearBackground.cpp
 	src/PoldiUtilities/PoldiTimeTransformer.cpp
 	src/PoldiUtilities/UncertainValue.cpp
@@ -84,6 +85,7 @@ set ( INC_FILES
 	inc/MantidSINQ/PoldiUtilities/PoldiPeak.h
 	inc/MantidSINQ/PoldiUtilities/PoldiPeakCollection.h
 	inc/MantidSINQ/PoldiUtilities/PoldiResidualCorrelationCore.h
+	inc/MantidSINQ/PoldiUtilities/PoldiSpectrumConstantBackground.h
         inc/MantidSINQ/PoldiUtilities/PoldiSpectrumDomainFunction.h
 	inc/MantidSINQ/PoldiUtilities/PoldiSpectrumLinearBackground.h
 	inc/MantidSINQ/PoldiUtilities/PoldiTimeTransformer.h
@@ -124,6 +126,7 @@ set ( TEST_FILES
 	PoldiResidualCorrelationCoreTest.h
         PoldiSourceSpectrumTest.h
         PoldiSpectrumDomainFunctionTest.h
+	PoldiSpectrumConstantBackgroundTest.h
 	PoldiSpectrumLinearBackgroundTest.h
 	PoldiTimeTransformerTest.h
 	PoldiTruncateDataTest.h
@@ -144,9 +147,9 @@ set_target_properties ( SINQ PROPERTIES OUTPUT_NAME MantidSINQ
 # Add to the 'Framework' group in VS
 set_property ( TARGET SINQ PROPERTY FOLDER "MantidFramework" )
 
-include_directories ( inc ../MDEvents/inc )
+include_directories ( inc ../MDEvents/inc ../CurveFitting/inc )
 
-target_link_libraries ( SINQ ${MANTIDLIBS} MDEvents )
+target_link_libraries ( SINQ ${MANTIDLIBS} MDEvents CurveFitting )
 
 # Add the unit tests directory
 add_subdirectory ( test )

Code/Mantid/Framework/SINQ/inc/MantidSINQ/PoldiUtilities/PoldiSpectrumConstantBackground.h

@@ -0,0 +1,62 @@
+#ifndef MANTID_SINQ_POLDISPECTRUMCONSTANTBACKGROUND_H_
+#define MANTID_SINQ_POLDISPECTRUMCONSTANTBACKGROUND_H_
+
+#include "MantidSINQ/DllConfig.h"
+#include "MantidCurveFitting/FlatBackground.h"
+#include "MantidSINQ/PoldiUtilities/IPoldiFunction1D.h"
+
+namespace Mantid {
+namespace Poldi {
+
+/** PoldiSpectrumConstantBackground
+
+    The function inherits from FlatBackground and also implements the
+    IPoldiFunction1D interface.
+
+        @author Michael Wedel, Paul Scherrer Institut - SINQ
+        @date 07/01/2015
+
+    Copyright © 2015 PSI-MSS
+
+    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 MANTID_SINQ_DLL PoldiSpectrumConstantBackground
+    : public CurveFitting::FlatBackground,
+      public IPoldiFunction1D {
+public:
+  PoldiSpectrumConstantBackground();
+  virtual ~PoldiSpectrumConstantBackground();
+
+  virtual std::string name() const { return "PoldiSpectrumConstantBackground"; }
+
+  virtual void setWorkspace(boost::shared_ptr<const API::Workspace> ws);
+  size_t getTimeBinCount() const;
+
+  virtual void poldiFunction1D(const std::vector<int> &indices,
+                               const API::FunctionDomain1D &domain,
+                               API::FunctionValues &values) const;
+
+protected:
+  size_t m_timeBinCount;
+};
+
+} // namespace Poldi
+} // namespace Mantid
+
+#endif /* MANTID_SINQ_POLDISPECTRUMCONSTANTBACKGROUND_H_ */

Code/Mantid/Framework/SINQ/src/PoldiUtilities/PoldiSpectrumConstantBackground.cpp

@@ -0,0 +1,49 @@
+#include "MantidSINQ/PoldiUtilities/PoldiSpectrumConstantBackground.h"
+#include "MantidAPI/FunctionFactory.h"
+#include "MantidAPI/MatrixWorkspace.h"
+
+namespace Mantid {
+namespace Poldi {
+
+using namespace CurveFitting;
+using namespace API;
+
+DECLARE_FUNCTION(PoldiSpectrumConstantBackground)
+
+/// Default constructor
+PoldiSpectrumConstantBackground::PoldiSpectrumConstantBackground()
+    : FlatBackground(), IPoldiFunction1D(), m_timeBinCount(0) {}
+
+/// Destructor
+PoldiSpectrumConstantBackground::~PoldiSpectrumConstantBackground() {}
+
+void PoldiSpectrumConstantBackground::setWorkspace(
+    boost::shared_ptr<const API::Workspace> ws) {
+  MatrixWorkspace_const_sptr matrixWs =
+      boost::dynamic_pointer_cast<const MatrixWorkspace>(ws);
+
+  if (matrixWs && matrixWs->getNumberHistograms() > 0) {
+    m_timeBinCount = matrixWs->readX(0).size();
+  }
+}
+
+size_t PoldiSpectrumConstantBackground::getTimeBinCount() const {
+  return m_timeBinCount;
+}
+
+void PoldiSpectrumConstantBackground::poldiFunction1D(
+    const std::vector<int> &indices, const API::FunctionDomain1D &domain,
+    API::FunctionValues &values) const {
+  double backgroundDetector = getParameter(0);
+  double wireCount = static_cast<double>(indices.size());
+  double distributionFactor = wireCount * static_cast<double>(m_timeBinCount) /
+                              static_cast<double>(domain.size());
+  double backgroundD = backgroundDetector * distributionFactor;
+
+  for (size_t i = 0; i < values.size(); ++i) {
+    values.addToCalculated(i, backgroundD);
+  }
+}
+
+} // namespace SINQ
+} // namespace Mantid

Code/Mantid/Framework/SINQ/test/PoldiSpectrumConstantBackgroundTest.h

@@ -0,0 +1,79 @@
+#ifndef MANTID_SINQ_POLDISPECTRUMCONSTANTBACKGROUNDTEST_H_
+#define MANTID_SINQ_POLDISPECTRUMCONSTANTBACKGROUNDTEST_H_
+
+#include <cxxtest/TestSuite.h>
+
+#include "MantidSINQ/PoldiUtilities/PoldiSpectrumConstantBackground.h"
+
+#include "MantidAPI/FrameworkManager.h"
+#include "MantidAPI/FunctionFactory.h"
+#include "MantidTestHelpers/WorkspaceCreationHelper.h"
+
+using namespace Mantid::API;
+using namespace Mantid::Poldi;
+
+class PoldiSpectrumConstantBackgroundTest : 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 PoldiSpectrumConstantBackgroundTest *createSuite() { return new PoldiSpectrumConstantBackgroundTest(); }
+    static void destroySuite( PoldiSpectrumConstantBackgroundTest *suite ) { delete suite; }
+
+    PoldiSpectrumConstantBackgroundTest()
+    {
+        FrameworkManager::Instance();
+    }
+
+    void testParameterCount()
+    {
+        PoldiSpectrumConstantBackground function;
+        function.initialize();
+
+        TS_ASSERT_EQUALS(function.nParams(), 1);
+    }
+
+    void testFunction()
+    {
+        IFunction_sptr function = FunctionFactory::Instance().createFunction("PoldiSpectrumConstantBackground");
+        MatrixWorkspace_sptr ws = WorkspaceCreationHelper::Create2DWorkspaceWhereYIsWorkspaceIndex(20, 2);
+
+        TS_ASSERT_THROWS_NOTHING(function->setWorkspace(ws));
+        function->setParameter(0, 10.0);
+
+        FunctionDomain1DVector domain(ws->readX(0));
+        FunctionValues values(domain);
+
+        function->function(domain, values);
+
+        TS_ASSERT_EQUALS(values[0], 10.0);
+        TS_ASSERT_EQUALS(values[1], 10.0);
+    }
+
+    void testPoldiFunction1D()
+    {
+        IFunction_sptr function = FunctionFactory::Instance().createFunction("PoldiSpectrumConstantBackground");
+        MatrixWorkspace_sptr ws = WorkspaceCreationHelper::Create2DWorkspace123(20, 2);
+
+        TS_ASSERT_THROWS_NOTHING(function->setWorkspace(ws));
+        function->setParameter(0, 10.0);
+
+        FunctionDomain1DVector domain(0.0, 10.0, 100);
+        FunctionValues values(domain);
+
+        // workspace has 20 spectra, value does not matter for function
+        std::vector<int> indices(20, 1);
+
+        boost::shared_ptr<IPoldiFunction1D> poldiFunction = boost::dynamic_pointer_cast<IPoldiFunction1D>(function);
+        TS_ASSERT(poldiFunction);
+        poldiFunction->poldiFunction1D(indices, domain, values);
+
+        for(size_t i = 0; i < values.size(); ++i) {
+            TS_ASSERT_EQUALS(values[i], 4.0)
+        }
+    }
+
+};
+
+
+#endif /* MANTID_SINQ_POLDISPECTRUMCONSTANTBACKGROUNDTEST_H_ */