LoadNexusMonitors dialog.
Table of Contents
| Name | Direction | Type | Default | Description |
|---|---|---|---|---|
| Filename | Input | string | Mandatory | The name (including its full or relative path) of the NeXus file to attempt to load. The file extension must either be .nxs or .NXS. Allowed extensions: [‘.nxs’] |
| OutputWorkspace | Output | Workspace | Mandatory | The name of the output workspace in which to load the NeXus monitors. |
| MonitorsAsEvents | Input | boolean | True | If enabled (by default), load the monitors as events (into an EventWorkspace), as long as there is event data. If disabled, load monitors as spectra (into a Workspace2D, regardless of whether event data is found. |
| LoadEventMonitors | Input | boolean | True | Load event monitor in NeXus file both event monitor and histogram monitor found in NeXus file.If both of LoadEventMonitor and LoadHistoMonitor are true, or both of them are false,then it is in the auto mode such that any existing monitor will be loaded. |
| LoadHistoMonitors | Input | boolean | True | Load histogram monitor in NeXus file both event monitor and histogram monitor found in NeXus file.If both of LoadEventMonitor and LoadHistoMonitor are true, or both of them are false,then it is in the auto mode such that any existing monitor will be loaded. |
This algorithm loads all monitors found in a NeXus file into a single Workspace2D (if there is no event data or if MonitorsAsEvents is false) or into an EventWorkspace (if event monitor data is found). The algorithm assumes that all of the monitors are histograms and have the same bin boundaries. NOTE: The entry is assumed to be in SNS or ISIS format, so the loader is currently not generically applicable.
This version (v2) fixes a bug in the first version and now returns a group workspace when invoked from Python with a multiperiod input workspace. As a side-effect of the fix, the contained individual workspaces for each of the periods are named slightly differently.
There are two types of monitors, event monitors and histograms monitors. Both of them are of class NXmonitor in NeXus file.
- Event monitor must contain all of the following three entries: * event_index * event_time_offset * event_time_zero
- Histogram monitor must contain entry * data * period_index
ISIS monitor of event mode may contain entry data. In this case, the monitor of event mode can be loaded in histogram mode.
There are a few use cases to load monitor’s data if the NeXus file has coexisting event monitors and histogram monitors.
- Load all monitors as histogram. * requirement: all event monitors have entry data; * Set MonitorsAsEvents to False, LoadEventMonitor to True and LoadHistoMonitor to True;
- Load monitors in event mode only. * Set MonitorsAsEvents to True, LoadEventMonitor to True and LoadHistoMonitor to False;
- Load monitors in histogram mode only. * Set MonitorsAsEvents to False, LoadEventMonitor to False and LoadHistoMonitor to True.
Note
To run these usage examples please first download the usage data, and add these to your path. In MantidPlot this is done using Manage User Directories.
ws = LoadNexusMonitors("CNCS_7860_event.nxs")
# CNCS has 3 monitors
print "Number of monitors =", ws.getNumberHistograms()
Output:
Number of monitors = 3
Categories: Algorithms | DataHandling\Nexus