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The aim of this exercise is to write a small algorithm that wraps a small script that focuses some powder diffraction data.
# Write an algorithm called PowerDiffractionReduce
# - The algorithm should have 3 properties:
# - Filename: A FileProperty for a TOF data file to load (ignore extensions)
# - CalFilename: A FileProperty for a cal file (ignore extensions)
# - OutputWorkspace: An output WorkspaceProperty to hold the final result.
# The steps the algorithm should perform are
# - Use the Load algorithm to load the TOF data
# - Apply the calibration file using ApplyDiffCalc
# - Run ConvertUnits on the TOF data to convert to dSpacing
# - Run DiffractionFocusing on the previous output & focus the data using the same cal file from the earlier step
# (called a grouping file here)
# - Set the output from the DiffractionFocussing algorithm as the output of PowerDiffractionReduce.
# - Delete the temporary reference using DeleteWorkspace
# To test the algorithm, execute the script that contains the algorithm to register it with Mantid. It will then
# show up in the list of algorithms. Use the following inputs:
# - Filename: HRP39182.RAW
# - CalFilename: hrpd_new_072_01_corr.cal
# - OutputWorkspace: focussed
from mantid.kernel import *
from mantid.api import *
# Class definition
class DiffractionPowderReduce(PythonAlgorithm):
def category(self):
return "Examples"
def PyInit(self):
# 2 input properties
self.declareProperty(FileProperty(name="Filename", defaultValue="", action=FileAction.Load),
doc="TOF data filename")
self.declareProperty(FileProperty(name="CalFilename", defaultValue="", action=FileAction.Load),
doc="TOF data filename")
# 1 Output property
self.declareProperty(WorkspaceProperty(name="OutputWorkspace", defaultValue="",
direction=Direction.Output))
def PyExec(self):
from mantid.simpleapi import Load, ApplyDiffCal, ConvertUnits, DiffractionFocussing, DeleteWorkspace
# Load file to workspace
_tmpws = Load(Filename=self.getPropertyValue("Filename"))
# Apply Calibration and Convert Units
calfile = self.getProperty("CalFilename").value
ApplyDiffCal(InstrumentWorkspace=_tmpws, CalibrationFile=calfile)
_tmpws = ConvertUnits(InputWorkspace=_tmpws, Target="dSpacing")
# Focus
_tmpws = DiffractionFocussing(InputWorkspace=_tmpws, GroupingFileName=calfile)
# Store reference after algorithm has gone
self.setProperty("OutputWorkspace", _tmpws)
DeleteWorkspace(_tmpws)
# Register algorithm with Mantid
AlgorithmFactory.subscribe(DiffractionPowderReduce)