Create saveRMCProfile algorithm framework

This creates the framework for a saveRMCProfile algorithm that would be used for saving spectral density data in a format that can be read by RMCProfile.
TODO get propper format of metadata

re: #27774

Framework/DataHandling/CMakeLists.txt

@@ -183,6 +183,7 @@ set(SRC_FILES
     src/SaveReflCustomAscii.cpp
     src/SaveReflThreeColumnAscii.cpp
     src/SaveReflectometryAscii.cpp
+    src/SaveRMCProfile.cpp
     src/SaveSESANS.cpp
     src/SaveSPE.cpp
     src/SaveSampleEnvironmentAndShape.cpp
@@ -382,6 +383,7 @@ set(INC_FILES
     inc/MantidDataHandling/SaveReflCustomAscii.h
     inc/MantidDataHandling/SaveReflThreeColumnAscii.h
     inc/MantidDataHandling/SaveReflectometryAscii.h
+    inc/MantidDataHandling/SaveRMCProfile.h
     inc/MantidDataHandling/SaveSESANS.h
     inc/MantidDataHandling/SaveSPE.h
     inc/MantidDataHandling/SaveSampleEnvironmentAndShape.h
@@ -567,6 +569,7 @@ set(TEST_FILES
     SaveReflCustomAsciiTest.h
     SaveReflThreeColumnAsciiTest.h
     SaveReflectometryAsciiTest.h
+    SaveRMCProfileTest.h
     SaveSESANSTest.h
     SaveSPETest.h
     SaveSampleEnvironmentAndShapeTest.h

Framework/DataHandling/inc/MantidDataHandling/SaveRMCProfile.h

+// Mantid Repository : https://github.com/mantidproject/mantid
+//
+// Copyright © 2020 ISIS Rutherford Appleton Laboratory UKRI,
+//     NScD Oak Ridge National Laboratory, European Spallation Source
+//     & Institut Laue - Langevin
+// SPDX - License - Identifier: GPL - 3.0 +
+#ifndef MANTID_DATAHANDLING_SAVERMCPROFILE_H_
+#define MANTID_DATAHANDLING_SAVERMCPROFILE_H_
+
+#include "MantidAPI/Algorithm.h"
+#include "MantidKernel/System.h"
+
+namespace Mantid {
+namespace DataHandling {
+
+/** SaveRMCProfile : Saves a workspace containing a spectral density in 
+a format readable by the RMCProfile package.
+
+Required Properties:
+<UL>
+<LI> InputWorkspace - An input workspace with units of Q </LI>
+<LI> Filename - The filename to use for the saved data </LI>
+</UL>
+ */
+class DLLExport SaveRMCProfile : public API::Algorithm {
+public:
+  const std::string name() const override;
+  int version() const override;
+  const std::vector<std::string> seeAlso() const override {
+    return {"SaveRMCProfile"};
+  }
+  const std::string category() const override;
+  const std::string summary() const override;
+  std::map<std::string, std::string> validateInputs() override;
+
+private:
+  void init() override;
+  void exec() override;
+  void writeMetaData(std::ofstream &out,
+                                     API::MatrixWorkspace_const_sptr inputWS);
+  void writeWSData(std::ofstream &out,
+                                   API::MatrixWorkspace_const_sptr inputWS);
+};
+
+} // namespace DataHandling
+} // namespace Mantid
+
+#endif /* MANTID_DATAHANDLING_SAVERMCPROFILE_H_ */

Framework/DataHandling/src/SaveRMCProfile.cpp

+// Mantid Repository : https://github.com/mantidproject/mantid
+//
+// Copyright © 2020 ISIS Rutherford Appleton Laboratory UKRI,
+//     NScD Oak Ridge National Laboratory, European Spallation Source
+//     & Institut Laue - Langevin
+// SPDX - License - Identifier: GPL - 3.0 +
+#include "MantidDataHandling/SaveRMCProfile.h"
+
+#include "MantidAPI/Axis.h"
+#include "MantidAPI/FileProperty.h"
+#include "MantidAPI/MatrixWorkspace.h"
+#include "MantidAPI/Run.h"
+#include "MantidKernel/MantidVersion.h"
+#include "MantidKernel/Unit.h"
+
+#include <fstream>
+
+namespace Mantid {
+namespace DataHandling {
+
+using Mantid::API::WorkspaceProperty;
+using Mantid::Kernel::Direction;
+
+// Register the algorithm into the AlgorithmFactory
+DECLARE_ALGORITHM(SaveRMCProfile)
+
+/// Algorithm's name for identification. @see Algorithm::name
+const std::string SaveRMCProfile::name() const { return "SaveRMCProfile"; }
+
+/// Algorithm's version for identification. @see Algorithm::version
+int SaveRMCProfile::version() const { return 1; }
+
+/// Algorithm's category for identification. @see Algorithm::category
+const std::string SaveRMCProfile::category() const { return "DataHandling\\Text"; }
+
+/// Algorithm's summary for use in the GUI and help. @see Algorithm::summary
+const std::string SaveRMCProfile::summary() const {
+  return "Save files readable by RMCProfile";
+}
+
+/** Initialize the algorithm's properties.
+ */
+void SaveRMCProfile::init() {
+  declareProperty(std::make_unique<WorkspaceProperty<>>("InputWorkspace", "",
+                                                        Direction::Input),
+                  "An input workspace with units of Q.");
+  declareProperty(std::make_unique<API::FileProperty>(
+                      "Filename", "", API::FileProperty::Save, ".gr"),
+                  "The filename to use for the saved data");
+}
+
+/// @copydoc Algorithm::validateInputs
+std::map<std::string, std::string> SaveRMCProfile::validateInputs() {
+  std::map<std::string, std::string> result;
+
+  // check for null pointers - this is to protect against workspace groups
+  API::MatrixWorkspace_const_sptr inputWS = getProperty("InputWorkspace");
+  if (!inputWS) {
+    return result;
+  }
+
+  const auto nHist = static_cast<int>(inputWS->getNumberHistograms());
+  if (nHist != 1) {
+    result["InputWorkspace"] = "Workspace must contain only one spectrum";
+  } else if (std::string(inputWS->getAxis(0)->unit()->label()) != "Angstrom^-1") {
+    result["InputWorkspace"] = "Expected x-units of Angstrom^-1";
+  }
+
+  return result;
+}
+
+/** Execute the algorithm.
+ */
+void SaveRMCProfile::exec() {
+  API::MatrixWorkspace_const_sptr inputWS = getProperty("InputWorkspace");
+  const std::string filename = getProperty("Filename");
+
+  // --------- open the file
+  std::ofstream out;
+  out.open(filename.c_str(), std::ios_base::out);
+
+  // --------- write the header in the style of required metadata
+  writeMetaData(out, inputWS);
+
+  // --------- write the data
+  writeWSData(out, inputWS);
+  
+  // --------- close the file
+  out.close();
+}
+
+void SaveRMCProfile::writeMetaData(std::ofstream& out,
+	API::MatrixWorkspace_const_sptr inputWS) {
+  out << "#example comment";
+}
+
+void SaveRMCProfile::writeWSData(std::ofstream& out,
+                                 API::MatrixWorkspace_const_sptr inputWS) {
+  const auto &x = inputWS->x(0);
+  const auto &y = inputWS->y(0);
+  const auto &dy = inputWS->e(0);
+  HistogramData::HistogramDx dx(y.size(), 0.0);
+  if (inputWS->sharedDx(0))
+    dx = inputWS->dx(0);
+  const size_t length = x.size();
+  if (x.size() == y.size()) {
+    for (size_t i = 0; i < length; ++i) {
+      out << "  " << x[i] << "  " << y[i] << "  " << dx[i] << "  " << dy[i]
+          << "\n";
+    }
+  } else {
+    for (size_t i = 0; i < length - 1; ++i) {
+      out << "  " << (x[i] + x[i + 1]) / 2.0 << "  " << y[i] << "  " << dx[i]
+          << "  " << dy[i] << "\n";
+    }
+  }
+}
+
+} // namespace DataHandling
+} // namespace Mantid

docs/source/algorithms/SaveRCMProfile-v1.rst

+
+.. algorithm::
+
+.. summary::
+
+.. relatedalgorithms::
+
+.. properties::
+
+Description
+-----------
+
+This algorithm saves S(Q)-1 files consistent with `RMCProfile <http://www.rmcprofile.org/Main_Page>`_.
+The body of the file is of the form ``Q SQ-1 dQ dSQ``.
+
+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 - SaveRMCProfile**
+
+.. testcode:: SaveRMCProfileExample
+
+   # Create a host workspace
+   ws = CreateWorkspace(DataX=range(0,3), DataY=range(0,3), UnitX="Angstrom^-1")
+
+   # Create a filename
+   import os
+   path = os.path.join(os.path.expanduser("~"), "savermcprofile.gr")
+
+   # Save as S(Q)-1 file
+   SavePDFGui(ws, path)
+
+   # Check that the file exists
+   print(os.path.isfile(path))
+
+Output:
+
+.. testoutput:: SaveRMCProfileExample
+
+    True
+
+.. testcleanup:: SaveRMCProfileExample
+
+   DeleteWorkspace(ws)
+   import os
+   try:
+       path = os.path.join(os.path.expanduser("~"), "savermcprofile.gr")
+       os.remove(path)
+   except:
+       pass
+
+.. categories::
+
+.. sourcelink::
+