ResNorm v2

Summary

Creates a group normalisation file by taking a resolution file

and fitting it to all the groups in the resolution (vanadium) reduction.

Properties

Name	Direction	Type	Default	Description
ResolutionWorkspace	Input	MatrixWorkspace	Mandatory	Workspace containing resolution
VanadiumWorkspace	Input	MatrixWorkspace	Mandatory	Workspace containing reduction of vanadium run
EnergyMin	Input	number	-0.2	Minimum energy for fit. Default=-0.2
EnergyMax	Input	number	0.2	Maximum energy for fit. Default=0.2
CreateOutput	Input	boolean	False	Create additional fitting output
OutputWorkspace	Output	WorkspaceGroup	Mandatory	Fitted parameter output
OutputWorkspaceTable	Output	TableWorkspace		Table workspace of fit parameters

Description

This algorithm fits the variation of the width of the resolution file to give a stretch factor and fits the peak intensities by normalising the peak area to unity and performing a linear fit with the vanadium.

The outpout workspace is a WorkspaceGroup containing two MatrixWorkspaces named _Intensity and _Stretch with the fitted parameters.

Workflow

Usage

Example - a basic example using ResNorm.

def createSampleWorkspace(name, num_spec=10, random=False):
  """
  Creates a sample workspace with a single lorentzian that looks like IRIS data
  """
  import os

  # Create sample data
  function = "name=Lorentzian,Amplitude=8,PeakCentre=5,FWHM=0.7"
  ws = CreateSampleWorkspace("Histogram",
                             Function="User Defined",
                             UserDefinedFunction=function,
                             XUnit="DeltaE",
                             Random=random,
                             XMin=0,
                             XMax=10,
                             BinWidth=0.01)

  # Reduce number of spectra
  ws = CropWorkspace(ws,
                     StartWorkspaceIndex=0,
                     EndWorkspaceIndex=num_spec-1)

  ws = ScaleX(ws, -5, "Add")
  ws = ScaleX(ws, 0.1, "Multiply")

  # Load instrument and instrument parameters
  LoadInstrument(ws, InstrumentName='IRIS', RewriteSpectraMap=True)
  path = os.path.join(config['instrumentDefinition.directory'], 'IRIS_graphite_002_Parameters.xml')
  LoadParameterFile(ws, Filename=path)
  ws = RenameWorkspace(ws, OutputWorkspace=name)

  return ws


van = createSampleWorkspace("irs26173_graphite002_red", random=True)
res = createSampleWorkspace("irs26173_graphite002_res", num_spec=1)

res_norm = ResNorm(ResolutionWorkspace=res,
                   VanadiumWorkspace=van,
                   Version=2)

Categories: AlgorithmIndex | Workflow\MIDAS

Source

Python: ResNorm2.py