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# Muon Analysis¶

## Interfaces¶

### ALC¶

• Choosing run_start or run_end as the log value will now work correctly - the values are taken as seconds relative to the start time of the first run.

### Muon Analysis¶

#### Multi-dataset fitting¶

The Data Analysis tab of the Muon Analysis interface has been updated to enable simultaneous fits of multiple datasets. A full explanation of how to use this new functionality is contained in the interface’s documentation. Results tables of these new kinds of fit can also be created.

As this is a new change for this release, please report any bugs, or requests for enhancements, to the development team. If you find a bug that stops you working, or would simply prefer to stick with the previous UI, just check the “Compatibility mode” box on the Settings tab and this will revert the interface to how it was in Mantid 3.7.

#### Other fixes and enhancements:¶

• When reusing the same plot window, an option has been added on the Settings tab to control how many previous fits are kept. It can be adjusted to 0 (remove all previous fits; default pre-Mantid 3.7), 1 (keep just one previous fit plus this one; new default) or higher.

• run_start and run_end are now available as log values to use in the results table. They can be inserted either as text (ISO-formatted date strings) or as seconds since the start of the first run.

• Documentation has been moved to the Mantid help system.

• A bug was fixed where, when plotting the log of counts and then switching to plot counts or asymmetry, the y axis was left as a logarithmic axis.

## Algorithms¶

• MaxEnt: MaxEnt has a new property, ComplexImage, which can be set to False when the imaginary part of the image should not be taken into account for the calculations.

• MaxEnt: The expression for the second derivative of real (pos/neg) images has been corrected.

• MaxEnt: The reconstructed image is always a point data workspace. The reconstructed data is of the same type as the input workspace.

• CalMuonDetectorPhases: the Frequency parameter is now supplied in MHz rather than megaradians per second.

• CalMuonDetectorPhases: The first column of the output phase table now shows spectrum numbers rather than workspace indices.

• PlotAsymmetryByLogValue: If run_start or run_end are chosen as the log to use, the values are taken as seconds relative to the start time of the first run.

• LoadMuonNexus: Fixed loading of certain v1 NeXus files converted from other formats that did not contain number of good frames.

• LoadMuonNexus: Now loads the correct detector IDs, whether the whole file is loaded or just a selection of spectra. Correctly handles muon v2 Nexus files, in which one spectrum can map to multiple detectors.

## Fit Functions¶

• Keren: A bug was fixed so that the field comes out in the correct units.

Full list of changes on GitHub.