Muon Analysis Unscripted Testing: Group 2 (Fitting)¶

Test 1: individual fit¶

• On the Home tab, select instrument EMU and load EMU00020918.nxs.
• Go to Data Analysis tab. Expand the window if the function browser is too small (you can drag the bar underneath it to set relative sizes of the widgets).
• The loaded dataset should be pre-selected: “20918” in Runs and “All Pairs” selected in the data table.
• “Label” box and “Co-add/Simultaneous” radio buttons should be disabled
• Click and drag blue lines on graph, check start/end times are updated.
• Check the reverse - change start/end times and blue lines should be updated on graph.
• Set up the interface to look like this. Note the non-default values for f1.Omega and f1.Sigma:

• Fit the data. Graph should be updated.

Test 2: sequential fit¶

• With everything set up as in the picture above, click Fit/Sequential fit. (Runs should still be set to “20918”, a single run).
• Dialog should appear. In the runs box of the new dialog that appears, type “20918-20” and hit Start
• Sequential fit of runs 20918, 20919, 20920 should happen one after the other

Test 3: co-added fit¶

• Stale errors should be cleared from the function browser.
• Click the “Co-add” button.
• The “Label” box will now be disabled
• In the drop-down, there should only be one workspace (EMU00020918-20; Pair; long; Asym; #1)
• Fit as before. Graph should be updated.

Test 4: simultaneous fit across runs¶

• With the same runs (20918-20) selected, select the “Simultaneous” radio button option.
• Drop-down list should have three workspaces in it now, for the three runs that will be fitted.
• The “Label” box should be enabled. By default, this will contain the run number string (“20918-20”) - add “SimFit” to the end of the string.
• Keep the same fit function, but use the “Global” checkboxes to mark A, Omega, Phi and Sigma as global.
• Fit the data. Note that plot will not be updated at present. (If you want to plot results, see the MuonSimulFit_20918-20SimFit workspace group)
• Use the << and >> buttons, or drop-down list, to see the fitted parameters for each run in the function browser.

Test 5: simultaneous fit across groups¶

• Type “20918” only in the “Runs” box
• The “Label” box should now read “20918”
• Select both “fwd” and “bwd” as groups, deselect “long”
• Keep fit function and global parameters as before
• Fit data
• Now try to fit again, without changing anything. It should warn you that the label “20918” has already been used - say no to overwriting and it should automatically increment the label to “20918#2”

Test 6: sequential fit of simultaneous fits¶

• Keep the same setup as Test 5, i.e. Runs=”20918” and “All Groups” selected
• Click Fit/Sequential fit to launch the dialog
• If offered the choice, choose not to overwrite the label
• Dialog should appear. In this new dialog (not the interface underneath):
  • Runs = “20918-20”
  • Label = “LabelSeq”
  • Hit “Start”
• This should fit the fwd and bwd groups simultaneously for each run 20918, 20919, 20920 in sequence.

Test 7: simultaneous fit across periods¶

The data used so far is single period, so here we will use MUSR data from the unit test data.

• Go back to the Home tab, set instrument to MUSR
• Load run 15189 and switch to Data Analysis tab
• (If any fit curves are still displayed, clear them with Display ‣ Clear fit curves)
• Two extra rows (Selected Periods and Periods to fit ) should have appeared in the data table. multi-period data.
• Note two points:
  • “All Pairs” should be selected - because “long” was loaded on the Home tab.
  • In the label box, the previous label “20918#2” has not been updated. This is because it contains a non-numeric character, so is assumed to be a user-set label (this is the intended behaviour).
• Set label to “MUSRlabel”
• Set fit function to LinearBackground (clear any existing function)
• Fit - periods will be fitted simultaneously

Test 8: TF Asymmetry fit¶

• Go back to the Home tab and load run 62260
• In the Data Analysis tab “TF Asymmetry Mode” should be ticked
• Set the “Groups/Pairs to fit” to “Custom”
• A pop-up should appear and make sure that only “fwd” is ticked
• Close the pop-up
• Clear the fitting functions
• Add a “Flat Background” and “GausOsc” functions.
• Set “Frequency” to 1.3
• Run a fit
• Look at the fitting parameters and notice that the “Flat Background” is non-zero (larger than the error)
• Remove the fitting functions
• Add a “GausOsc” function with “Frequency” set to 1.3
• Go to the fit menu and select TF Asymmetry Fit
• Clear the fit functions
• Add a “GausOsc” function and set “Frequency” to 1.3
• Then add a “Flat Background” to the fitting functions
• Run a normal Fit
• The “Flat Background” should now have a value of zero (less than the error)

Test 9: Multiple TF Asymmetry fits¶

• Go back to the Home tab and load run 62261
• In the Data Analysis tab “TF Asymmetry Mode” should be ticked
• Clear the fitting functions
• Add a “GausOsc” function with “Frequency” set to 1.3
• Tick the “Global” box for “Frequency” and “Sigma”
• Go to the fit menu and select TF Asymmetry Fit
• Then add a “Flat Background” to the fitting functions
• Tick the “Global” box for “Frequency” and “Sigma” (this will need doing again)
• Run a normal Fit
• The “Flat Background” should now have a value of zero (less than the error)