add option to generate table workspace, re #10967

Code/Mantid/Framework/PythonInterface/plugins/algorithms/EnginXCalibrate.py

@@ -1,6 +1,7 @@
 #pylint: disable=no-init,invalid-name
 from mantid.kernel import *
 from mantid.api import *
+from mantid.simpleapi import CreateEmptyTableWorkspace
 
 
 class EnginXCalibrate(PythonAlgorithm):
@@ -26,6 +27,12 @@ def PyInit(self):
                 Direction.Input, PropertyMode.Optional),\
     		"Calibrated detector positions. If not specified, default ones are used.")
 
+        self.declareProperty('OutputParametersTableName', '', direction=Direction.Input,
+                             doc = 'Name for a table workspace with the calibration parameters calculated by '
+                             'from this algorithm: difc and zero parameters for GSAS. At the moment '
+                             'these two parameters are added as two columns in a single row. If not given, no'
+                             'table is generated.')
+
         self.declareProperty("Difc", 0.0, direction = Direction.Output,\
     		doc = "Calibrated Difc value for the bank")
 
@@ -36,16 +43,33 @@ def PyExec(self):
 
         ws = self._focusRun()
 
+        difc, zero = self._fitParams(ws)
+
+        self._produceOutputs(difc, zero)
+
+    def _fitParams(self, focusedWS):
+        """
+        Fit the GSAS parameters that this algorithm produces: difc and zero
+
+        @param focusedWS: focused workspace to do the fitting on
+
+        @returns a pair of parameters: difc and zero
+        """
         fitPeaksAlg = self.createChildAlgorithm('EnginXFitPeaks')
-        fitPeaksAlg.setProperty('InputWorkspace', ws)
+        fitPeaksAlg.setProperty('InputWorkspace', focusedWS)
         fitPeaksAlg.setProperty('WorkspaceIndex', 0) # There should be only one index anyway
         fitPeaksAlg.setProperty('ExpectedPeaks', self.getProperty('ExpectedPeaks').value)
         fitPeaksAlg.execute()
 
-        self.setProperty('Difc', fitPeaksAlg.getProperty('Difc').value)
-        self.setProperty('Zero', fitPeaksAlg.getProperty('Zero').value)
+        difc = fitPeaksAlg.getProperty('Difc').value
+        zero = fitPeaksAlg.getProperty('Zero').value
+
+        return difc, zero
 
     def _focusRun(self):
+        """
+        Focuses the input workspace by running EnginXFocus which will produce a single spectrum workspace.
+        """
         alg = self.createChildAlgorithm('EnginXFocus')
         alg.setProperty('Filename', self.getProperty('Filename').value)
         alg.setProperty('Bank', self.getProperty('Bank').value)
@@ -58,5 +82,32 @@ def _focusRun(self):
 
         return alg.getProperty('OutputWorkspace').value
 
+    def _produceOutputs(self, difc, zero):
+        """
+        Just fills in the output properties as requested
+        @param difc :: the difc GSAS parameter as fitted here
+        @param zero :: the zero GSAS parameter as fitted here
+        """
+        self.setProperty('Difc', difc)
+        self.setProperty('Zero', zero)
+
+        # make output table if requested
+        tblName = self.getPropertyValue("OutputParametersTableName")
+        if '' != tblName:
+            self._generateOutputParTable(tblName)
+
+    def _generateOutputParTable(self, name):
+        """
+        Produces a table workspace with the two calibration parameters
+
+        @param name :: the name to use for the table workspace that is created here
+        """
+        tbl = CreateEmptyTableWorkspace(OutputWorkspace=name)
+        tbl.addColumn('double', 'difc')
+        tbl.addColumn('double', 'zero')
+        tbl.addRow([float(self.getPropertyValue('difc')), float(self.getPropertyValue('zero'))])
+
+        self.log().information("Output parameters added into a table workspace: %s" % name)
+
 
 AlgorithmFactory.subscribe(EnginXCalibrate)

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

@@ -15,10 +15,23 @@ Description
    removed without a notification, should instrument scientists decide to do so.
 
 
-Utilises  :ref:`algm-EnginXFocus` which performs a TOF to dSpacing conversion using calibrated pixel positions, focuses the values in dSpacing and then converts them back to TOF. 
-Then calls  :ref:`algm-EnginXFitPeaks` which through a sequence of peak fits determines a linear relationship between dSpacing and measured TOF values in terms of DIFC and ZERO values and provides the these parameters to the Calibrate algorithm.
-This algorithm provides an indirect calibration of the sample position, that is, a calibration returned in terms of Difc and Zero rather than an actual new sample position (hence the reason for 'indirect').
-
+Utilises :ref:`algm-EnginXFocus` which performs a TOF to dSpacing
+conversion using calibrated pixel positions, focuses the values in
+dSpacing and then converts them back to TOF.
+Then calls :ref:`algm-EnginXFitPeaks` which through a sequence of peak
+fits determines a linear relationship between dSpacing and measured
+TOF values in terms of DIFC and ZERO values and provides the these
+parameters to the Calibrate algorithm.
+
+This algorithm provides an indirect calibration of the sample
+position, that is, a calibration returned in terms of Difc and Zero
+rather than an actual new sample position (hence the reason for
+'indirect').
+
+The parameters DIFC and ZERO are returned and can be retrieved as
+output properties as well. If a name is given in
+OutputParametersTableName the algorithm also produces a table
+workspace with that name, containing the two output parameters.
 
 .. categories::
 
@@ -29,17 +42,28 @@ Usage
 
 **Example - Calculate Difc and Zero:**
 
-.. testcode:: Ex
+.. testcode:: ExampleCalib
 
+   out_tbl_name = 'out_params'
    Difc, Zero = EnginXCalibrate(Filename="ENGINX00213855.nxs",
-                                     ExpectedPeaks=[1.097, 2.1], Bank=1)
+                                ExpectedPeaks=[1.097, 2.1], Bank=1,
+                                OutputParametersTableName=out_tbl_name)
 
    print "Difc: %.2f" % (Difc)
    print "Zero: %.2f" % (Zero)
+   tbl = mtd[out_tbl_name]
+   print "The output table has %d row(s)" % tbl.rowCount()
+   print "Parameters from the table, Difc: %.2f, Zero: %.2f" % (tbl.cell(0,0), tbl.cell(0,1))
+
+.. testcleanup:: ExampleCalib
+
+   DeleteWorkspace(out_tbl_name)
 
 Output:
 
-.. testoutput:: Ex
+.. testoutput:: ExampleCalib
 
    Difc: 18404.93
    Zero: -10.89
+   The output table has 1 row(s)
+   Parameters from the table, Difc: 18404.93, Zero: -10.89