AccumulateMD v1

../_images/AccumulateMD-v1_dlg.png

AccumulateMD dialog.

Summary

Add new data to an existing MDHistoWorkspace

Properties

Name Direction Type Default Description
InputWorkspace Input MDEventWorkspace Mandatory An input MDEventWorkspace to append data to.
OutputWorkspace Output MDEventWorkspace Mandatory MDEventWorkspace with new data appended.
DataSources Input str list Mandatory Input workspaces to process, or filenames to load and process
EFix Input dbl list   datasource energy values in meV
Emode Input string Direct Analysis mode [‘Elastic’, ‘Direct’, ‘Indirect’]. Allowed values: [‘Elastic’, ‘Direct’, ‘Indirect’]
Alatt Input dbl list Mandatory Lattice parameters
Angdeg Input dbl list Mandatory Lattice angles
u Input dbl list Mandatory Lattice vector parallel to neutron beam
v Input dbl list Mandatory Lattice vector perpendicular to neutron beam in the horizontal plane
Psi Input dbl list   Psi rotation in degrees. Optional or one entry per run.
Gl Input dbl list   gl rotation in degrees. Optional or one entry per run.
Gs Input dbl list   gs rotation in degrees. Optional or one entry per run.
InPlace Input boolean False Execute conversions to MD and Merge in one-step. Less memory overhead.
Clean Input boolean False Create workspace from fresh rather than appending to existing workspace data.

Description

This workflow algorithm appends new data to an existing multidimensional workspace. It allows the accumulation of data in a single MDWorkspace as you go, e.g. during an experiment.

Input properties which are not described here are identical to those in the CreateMD v1 algorithm.

InputWorkspace

The MDEventWorkspace to append data to.

DataSources

These can be workspace names, file names or full file paths. Not all of the data need to exist when the algorithm is called. If data are named which have previously been appended to the workspace they will not be appended again. Note that data are known by name, it is therefore possible to append the same data again if the data source is renamed.

Clean

It is possible to get confused about what data has been included in an MDWorkspace if it is built up slowly over an experiment. Use this option to start afresh; it creates a new workspace using all of the data in DataSources which are available, rather then appending to the existing workspace.

Usage

Simple Example

# Create some sample data
sample_data_1 = CreateSimulationWorkspace(Instrument='MAR', BinParams=[-3,1,3], UnitX='DeltaE')
AddSampleLog(Workspace=sample_data_1,LogName='Ei',LogText='3.0',LogType='Number')
sample_data_2 = CreateSimulationWorkspace(Instrument='MAR', BinParams=[-3,1,3], UnitX='DeltaE')
AddSampleLog(Workspace=sample_data_2,LogName='Ei',LogText='3.0',LogType='Number')

# Create an MDWorkspace withdata from sample_data_1
md_ws = CreateMD(sample_data_1, Emode='Direct', Alatt=[1.4165, 1.4165,1.4165], Angdeg=[90, 90, 90], u=[1, 0, 0,], v=[0,1,0])

# Append data from sample_data_2 to the existing workspace
# Note: sample_data_1 will not be appended as it is already in the workspace
#       sample_data_3 will not be appended as it does not exist
acc_ws = AccumulateMD(md_ws, 'sample_data_1,sample_data_2,sample_data_3', Alatt=[1.4165, 1.4165, 1.4165], Angdeg=[90, 90, 90], u=[1, 0, 0,], v=[0,1,0])

# acc_ws should have double the number of events that md_ws has
print "There are {kwarg} events in each of the two data workspaces.".format(kwarg=md_ws.getNEvents())
print "The accumulated data workspace contains {kwarg} events.".format(kwarg=acc_ws.getNEvents())

Output:

There are 5508 events in each of the two data workspaces.
The accumulated data workspace contains 11016 events.

Categories: Algorithms | MDAlgorithms

Source

C++ source: AccumulateMD.cpp

C++ header: AccumulateMD.h