Framework Changes

Algorithms

New features

• Append Spectra has a new property RewriteSpectraMap to append two workspaces with spectra having same detector IDs at different positions by rewriting the spectrum to detector mapping.

Bugfixes

• Mantid now keeps asynchronously started algorithms, including live-data monitoring algorithms, active during startup so they can be cancelled safely if Mantid shuts down immediately.

• A mesh sample’s baked goniometer rotation is now saved to and loaded from NeXus, so a saved and reloaded sample is no longer rotated a second time. Files saved before this change, and samples in their own frame, load as unrotated exactly as before.

• On Windows, algorithms that split their work into tasks, such as LoadEventNexus v1, now respect the MultiThreaded.MaxCores setting rather than always using every core.

• ClearInstrumentParameters v1 now reports an error for workspaces with a detector scan, instead of silently discarding the scan and leaving the workspace in an inconsistent state.

• LoadParameterFile v1 now adds parameters whose values come from sample logs to the given workspace only. Previously they were also applied to every other workspace with the same instrument, including workspaces loaded later in the session, the next time their instrument parameters were refreshed from their logs.

• CopyInstrumentParameters no longer fails when the input workspace has masked detectors and its instrument differs from that of the output workspace. The masking is now copied along with the other parameters.

Deprecated

Removed

• The following deprecated algorithms have now been removed:

  • LoadSINQFocus (deprecated 2013-10-28). Use LoadSINQ v1 instead.

  • LoadPreNexus (deprecated 2025-04-10). There is no replacement.

  • LoadPreNexusMonitors (deprecated 2025-04-10). There is no replacement.

  • LoadEventPreNexus (deprecated 2025-05-06). There is no replacement.

  • LoadPreNexusLive (deprecated 2025-05-27), which depended on LoadEventPreNexus. There is no replacement.

• DetermineChunking v1 no longer accepts SNS _runinfo.xml (PreNeXus) files.

• DgsReduction v1 no longer loads monitors from PreNeXus _neutron_event.dat files when determining the incident energy.

• The algorithm IntegratePeaksMD v1 was deprecated in Release 6.13.0 and has now been removed. Use IntegratePeaksMD v2 instead.

• The algorithm IntegratePeaksCWSD was deprecated in Release 6.13.0 and has now been removed. There is no replacement. As a result, the Integrate Peaks button on the Scans Processing tab and the Integrate Peak button on the Peak Integration tab of the HFIR 4-Circle Reduction interface have been removed.

• Removed UnwrapMonitorsInTOF and UnwrapSNS (deprecated since release 6.13.0).

• Removed MaskInstrument (deprecated since release 5.1.0), use MaskDetectors instead.

• Removed version 1 of SCDCalibratePanels (deprecated since release 6.14.0), use SCDCalibratePanels v2 instead.

Fit Functions

New features

Bugfixes

• Fixed a crash in UserFunction1D when the function has no fitting parameters or all parameters are fixed. An error is now raised suggesting EvaluateFunction instead.

• Copying or saving a multi-domain fit function that contains an empty composite function, such as an empty ProductFunction, now keeps each member assigned to its own dataset. Previously, all members were assigned to the first dataset.

Deprecated

Removed

Data Objects

New features

Bugfixes

• componentInfo() and instrumentMetadata() now return the instrument of an experiment info that has not yet been read from its file, such as one in an MD workspace loaded with FileBackEnd in LoadMD v1, instead of an empty instrument.

Python

New features

• ComponentInfo in Python has new methods pixelGridXSize and pixelGridYSize for finding the physical size (in m) if a grid or rectangular detector.

• Workspaces now provide getLabFrameSampleShape, returning the sample shape as it sits in the lab frame, rotated by whatever part of the workspace’s goniometer rotation the shape does not already carry. The workspace’s own sample is left unchanged. A flat-plate shape offers no way to express a rotation, so it is taken to be defined in the frame it is meant to be used in and returned unchanged with a warning. A CSG shape rotated with RotateSampleShape v1 and saved by an earlier version cannot be told apart from one already in the lab frame, so getLabFrameSampleShape replaces that rotation with the workspace’s goniometer rotation rather than adding to it.

• Sample shapes now expose getAppliedRotation, the goniometer rotation baked into the shape. This says which frame the shape is in, not every rotation it has ever had: rotations that re-express the shape within its own frame - the XDegrees properties of LoadSampleShape v1, rotate-all tags and RotateSampleShape v1 - are excluded, so the identity means the shape is in its own frame however much its definition has been rotated within that frame.

• ComponentInfo has new methods getPositionParameter, getRotationParameter, getParameterAsString, getParameterVisible, getParamDescription, getParamShortDescription, getDescription, getShortDescription and setDescription. They give the same results as the methods of the same name on instrument components, so they can be used in their place. See Instrument Access via SpectrumInfo, DetectorInfo, ComponentInfo.

• ComponentInfo has a new method referenceFrame(), returning the instrument’s ReferenceFrame (which axes point up and along the beam), as Instrument.getReferenceFrame() did. Use it as workspace.componentInfo().referenceFrame(). See Instrument Access via SpectrumInfo, DetectorInfo, ComponentInfo.

• DetectorInfo and SpectrumInfo in Python have new methods phi and phiOffset, and new versions of twoTheta and signedTwoTheta that take an observer position and axis. These give the same results as getPhi, getPhiOffset, getTwoTheta and getSignedTwoTheta on detector objects, so they can be used in their place.

• IMDHistoWorkspace methods setSignalArray, setErrorSquaredArray and setNumEventsArray are now much faster for large arrays: setting the 160 million bins of a WAND scan takes 0.16 s instead of 19 s.

• MatrixWorkspace in Python has a new method getXMinMax, which returns the lowest and highest X values of all spectra or of the given workspace indices. Spectra with a non-finite first or last value are skipped unless includeNonFiniteSpectra is true, in which case they contribute their finite values.

Bugfixes

• Live data monitoring no longer stalls when C++ log messages are forwarded to Python while another Python thread holds the global interpreter lock.

• Deprecation and other warnings raised by Mantid’s Python API are now raised as the warning itself when Python is set to treat warnings as errors (for example with -W error or warnings.simplefilter("error")), making it possible to find deprecated calls this way. Previously they caused a SystemError instead.

• Python algorithms no longer deadlock during AlgorithmManager.shutdown() when they need to reacquire Python’s global interpreter lock (GIL) to finish.

• ComponentInfo method indexOfAny(name) now returns the same component as Instrument.getComponentByName(name) when several components share a name: the one closest to the root of the instrument. Previously it could return a different component with that name.

Deprecated

• Instrument.getBaseInstrument() is deprecated and now raises a DeprecationWarning. To get the instrument geometry before any moves, rotations or calibration were applied, use the new baseComponentInfo() method on the workspace, which returns a ComponentInfo with the same component indices as componentInfo(). See Instrument Access via SpectrumInfo, DetectorInfo, ComponentInfo.

Dependencies

New features

Bugfixes

MantidWorkbench

See Mantid Workbench Changes.

Release 7.1.0