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Framework Changes

Concepts

• mantid.kernel.IntArrayProperty now supports specifying step sizes

• Support has been added for negative indexing of WorkspaceGroups. Try ws_group[-1] to get the last workspace in the WorkspaceGroup ws_group.

• Updated the clone method of IFunction to copy parameter errors across as well as parameter values.

Algorithms

New

• RemoveSpectra is a new general purpose algorithm that enables you to optionally remove spectra from a workspace given one of 3 criteria, if it’s masked, if it doesn’t have a detector, and if presented in a user defined list.

Improvements

• All the ILL nexus file loaders were speeded up due to parallelization of the loading.

• LoadEventNexus has an additional option LoadNexusInstrumentXML = {Default, True}, which controls whether or not the embedded instrument definition is read from the NeXus file.

• The numerical integration absorption algorithms (AbsorptionCorrection, CuboidGaugeVolumeAbsorption, CylinderAbsorption, FlatPlateAbsorption) have been modified to use a more numerically stable method for performing the integration, pairwise summation.

• Improved support for thin-walled hollow cylinder shapes in MonteCarloAbsorption v1

• LoadSampleEnvironment and LoadSampleShape now support setting the scale of the stl to millimetres, centimetres, or metres. It also takes rotation as angles applied in order X then Y then Z, as opposed to a matrix.

• LoadSampleShape now rotates the sample based off of the setting of the goniometer.

• GenerateEventsFilter is able to accept any MatrixWorkspace, as long as it has run objects loaded from LoadNexusLogs, other than EventWorkspace.

• AbsorptionCorrection has a new property ScatterFrom which allows for calculating the correction for the other components (i.e. container and environment)

• SetSample can calculate the density from the sample mass

• We have prevented an error due to locale settings which may appear when reading, for instance, the incident energy Ei value from the logs in ConvertUnits and many other algorithms.

• Pseudo-Voigt has been modified to be more in line with FULLPROF and GSAS. One of its basic parameter, Height, is changed to Intensity.

• CalculatePolynomialBackground has an option to select the the minimizer used during fitting.

• CalculatePolynomialBackground has been modified to pass parameters with double precision to make it more correct.

• 10x performance improvement in calls to Mantid::PhysicalConstants::getAtom.

• SetSample will now look for facility wide sample environments. instrument specific ones will be loaded first.

• SolidAngle is extended to accommodate new options for fast analytical calculation for SANS-type detectors.

• FilterEvents has a property InformativeOutputNames which changes the name of output workspace to include the start and end time of the slice.

• SumOverlappingTubes v1 was speeded up due to parallelization of the actual histogramming step.

• CylinderAbsorption now has a CylinderAxis property to set the direction of the cylinder axis.

• SaveNexusProcessed now throws a clearer error on saving of nested groups of groups.

Instrument Definition Files

• A new attribute, name-count-increment, has been introduced to the <locations> tag which allows the auto-generated location names to be incremented by a user-defined amount.

• ARCS, CNCS, HYSPEC, NOMAD, POWGEN, SEQUOIA, SNAP, and VULCAN have had the axis that signed two-theta is calculated against changed from +y to +x

Bug fixes

• SetSample now correctly handles the Sample number density being passed as a string, before the algorithm would execute, but silently ignored the provided number density, the number density is now properly used.

• Mantid no longer crashed when invalid period logs encountered in LoadEventNexus <algm-LoadEventNexus>. A clear error message is displayed which explains the problem.

• ISIS sample logs are now correctly filtered by status and period on loading.

• A bug has been fixed in status log filtering where if a log contained times before the first running log entry then they would be included rather than excluded.

Removed

• The deprecated version 1 of the FindEPP algorithm has been removed. Use FindEPP-v2 instead.

Data Objects

• Added method isCommonLogBins to check if the MatrixWorkspace contains common X bins with logarithmic spacing.

Python

New

• The mantid.plots module now registers a power and square scale type to be used with set_xscale and set_xscale functions.

• In mantid.kernel.DateAndTime, the method total_nanoseconds() has been deprecated, totalNanoseconds() should be used instead.

• In mantid.kernel.time_duration, The method total_nanoseconds() has been deprecated, totalNanoseconds() should be used instead.

• mantid.geometry.DetectorInfo.indexOf has been exposed to python

• indices and slicepoint options have been added to mantid.plots to allow selection of which plane to plot from an MDHistoWorkspace. transpose has also been added to transpose the axes of any 2D plot.

Bugfixes

• The TypeError raised when calibrating tubes has been fixed.

Release 4.1.0