LoadEventPreNexus v2

../_images/LoadEventPreNexus-v2_dlg.png

LoadEventPreNexus dialog.

Summary

Loads SNS raw neutron event data format and stores it in a workspace.

Alias

This algorithm is also known as: LoadEventPreNeXus2

Properties

Name Direction Type Default Description
EventFilename Input string Mandatory The name of the neutron event file to read, including its full or relative path. In most cases, the file typically ends in neutron_event.dat (N.B. case sensitive if running on Linux). Allowed extensions: [‘_neutron_event.dat’, ‘_neutron0_event.dat’, ‘_neutron1_event.dat’, ‘_neutron2_event.dat’, ‘_neutron3_event.dat’, ‘_neutron4_event.dat’, ‘_live_neutron_event.dat’]
PulseidFilename Input string   File containing the accelerator pulse information; the filename will be found automatically if not specified. Allowed extensions: [‘_pulseid.dat’, ‘_pulseid0.dat’, ‘_pulseid1.dat’, ‘_pulseid2.dat’, ‘_pulseid3.dat’, ‘_pulseid4.dat’, ‘_live_pulseid.dat’]
MappingFilename Input string   File containing the pixel mapping (DAS pixels to pixel IDs) file (typically INSTRUMENT_TS_YYYY_MM_DD.dat). The filename will be found automatically if not specified. Allowed extensions: [‘.dat’]
SpectrumList Input int list   A list of individual spectra (pixel IDs) to read, specified as e.g. 10:20. Only used if set.
ChunkNumber Input number Optional If loading the file by sections (‘chunks’), this is the section number of this execution of the algorithm.
TotalChunks Input number Optional If loading the file by sections (‘chunks’), this is the total number of sections.
UseParallelProcessing Input string Auto Use multiple cores for loading the data? Auto: Use serial loading for small data sets, parallel for large data sets. Serial: Use a single core. Parallel: Use all available cores. Allowed values: [‘Auto’, ‘Serial’, ‘Parallel’]
OutputWorkspace Output IEventWorkspace Mandatory The name of the workspace that will be created, filled with the read-in data and stored in the [[Analysis Data Service]].
EventNumberWorkspace Output MatrixWorkspace   Workspace with number of events per pulse
DBOutputBlockNumber Input number Optional Index of the loading block for debugging output.
DBNumberOutputEvents Input number 40 Number of output events for debugging purpose. Must be defined with DBOutputBlockNumber.
DBNumberOutputPulses Input number Optional Number of output pulses for debugging purpose.

Description

The LoadEventPreNeXus algorithm stores data from the pre-nexus neutron event data file in an EventWorkspace. The default histogram bin boundaries consist of a single bin able to hold all events (in all pixels), and will have their units set to time-of-flight. Since it is an EventWorkspace, it can be rebinned to finer bins with no loss of data.

Optional properties

Specific pulse ID and mapping files can be specified if needed; these are guessed at automatically from the neutron filename, if not specified.

A specific list of pixel ids can be specified, in which case only events relating to these pixels will appear in the output.

The ChunkNumber and TotalChunks properties can be used to load only a section of the file; e.g. if these are 1 and 10 respectively only the first 10% of the events will be loaded.

Categories: Algorithms | DataHandling\PreNexus