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MergeRuns v1

Summary

Combines the data contained in an arbitrary number of input workspaces.

See Also

ConjoinWorkspaces

Properties

Name	Direction	Type	Default	Description
InputWorkspaces	Input	str list	Mandatory	The names of the input workspaces as a list. You may also group workspaces using the GUI or [[GroupWorkspaces]], and specify the name of the group instead.
OutputWorkspace	Output	Workspace	Mandatory	Name of the output workspace
SampleLogsTimeSeries	Input	string		A comma separated list of the sample logs to merge into a time series. The initial times are taken as the start times for the run. Sample logs must be numeric.
SampleLogsList	Input	string		A comma separated list of the sample logs to merge into a list.
SampleLogsWarn	Input	string		A comma separated list of the sample logs to generate a warning if different when merging.
SampleLogsWarnTolerances	Input	string		The tolerances for warning if sample logs are different. Can either be empty for a comparison of the strings, a single value for all warn sample logs, or a comma separated list of values (must be the same length as SampleLogsWarn).
SampleLogsFail	Input	string		The sample logs to fail if different when merging. If there is a difference the run is skipped.
SampleLogsFailTolerances	Input	string		The tolerances for failing if sample logs are different. Can either be empty for a comparison of the strings, a single value for all fail sample logs, or a comma separated list of values (must be the same length as SampleLogsFail).
SampleLogsSum	Input	string		A comma separated list of the sample logs to sum into a single entry. Sample logs must be numeric.
RebinBehaviour	Input	string	Rebin	Choose whether to rebin when bins are different, or fail (fail behaviour defined in FailBehaviour option). Allowed values: [‘Rebin’, ‘Fail’]
FailBehaviour	Input	string	Skip File	Choose whether to skip the file and continue, or stop and throw and error, when encountering a failure. Allowed values: [‘Skip File’, ‘Stop’]

Description

Combines the data contained in an arbitrary number of input workspaces. If the input workspaces do not have common binning, the bins in the output workspace will cover the entire range of all the input workspaces, with the largest bin widths used in regions of overlap.

The combination of each workspace is performed using the Plus v1 algorithm, this does not perform any weighting based on the duration of collection, or proton charge. If you wish to perform Merge runs that should not be equally weighted then they should be corrected individually prior to merging.

Restrictions on the input workspace

The input workspaces must contain histogram data with the same number of spectra and matching units and instrument name in order for the algorithm to succeed.

Workspace2Ds: Each input workspace must have common binning for all its spectra.

EventWorkspaces: This algorithm is Event-aware; it will append event lists from common spectra. Binning parameters need not be compatible; the output workspace will use the first workspaces’ X bin boundaries.

WorkspaceGroups: Each nested has to be one of the above.

Other than this it is currently left to the user to ensure that the combination of the workspaces is a valid operation.

Processing Group Workspaces

Multi-period Group Workspaces

Group workspaces will be merged respecting the periods within each group. For example if you have two multiperiod group workspaces A and B and an output workspace C. A contains matrix workspaces A_1 and A_2, and B contains matrix workspaces B_1 and B2. Since this is multiperiod data, A_1 and B_1 share the same period, as do A_2 and B_2. So merging must be with respect to workspaces of equivalent periods. Therefore, merging is conducted such that A_1 + B_1 = C_1 and A_2 + B_2 = C_2.

Group Workspaces that are not multiperiod

If group workspaces are provided that are not multi-period, this algorithm will merge across all nested workspaces, to give a single output matrix workspace.

Merging Sample Logs

Sample logs are optionally merged when running this algorithm. The behaviour when merging is defined in the instrument parameter file, but can be added to or overridden via this algorithm. Definitions in the XML file are given as shown in the example below. See the usage examples at the end of this document for examples of overriding the behaviour defined in the XML file.

When performing the tolerance check for the warn or fail options it is always with respect to the first workspace in the merge. When choosing via the GUI this will be the first workspace that was selected.

Note: this currently only works when the underlying workspaces being merged are Matrix Workspaces.

Note: The sample log in the merged workspace is replaced in the case of Sum, Time Series and List merges. This means these merge types can not be used together for a given sample log.

<parameter name="sample_logs_sum" type="string">
    <value val="duration, monitor1.monsum" />
</parameter>
<parameter name="sample_logs_time_series" type="string">
    <value val="sample.temperature, sample.pressure" />
</parameter>
<parameter name="sample_logs_list" type="string">
    <value val="run_number" />
</parameter>
<parameter name="sample_logs_warn" type="string">
    <value val="EPP, Fermi.phase, sample.temperature" />
</parameter>
<parameter name="sample_logs_warn_tolerances" type="string">
    <value val="5, 0.001, 50" />
</parameter>
<parameter name="sample_logs_fail" type="string">
    <value val="experiment_identifier, Ei, Fermi.rotation_speed" />
</parameter>
<parameter name="sample_logs_fail_tolerances" type="string">
    <value val="0, 0.1, 2" />
</parameter>

Merging Workspaces with Detector Scans

If the workspaces being merged contain detector scans then there are currently two options:

1. The workspaces have identical scan intervals

In this case the workspaces will be merged as they normally would be by MergeRuns, that is the counts in the two workspaces are summed. The detectors must have the same positions, rotations etc. for all time intervals, else the algorithm will throw.

2. The workspaces have different scan intervals

For this case the scan intervals must not overlap. The merged workspace histograms are appended to the end of the first workspace.

ChildAlgorithms used

The Rebin v1 algorithm is used, if necessary, to put all the input workspaces onto a common binning.

The Plus v1 algorithm is used to combine each of the workspaces together one pair at a time.

Usage

Example: Merge Two Workspaces

dataX = [1, 2, 3, 4, 5]
dataY = [6, 15, 21, 9]

a = CreateWorkspace(dataX, dataY)
b = CreateWorkspace(dataX, dataY)

merged = MergeRuns(InputWorkspaces="a, b")

print("a      = {}".format(a.readY(0)))
print("b      = {}".format(b.readY(0)))
print("merged = {}".format(merged.readY(0)))

Output:

a      = [ 6. 15. 21.  9.]
b      = [ 6. 15. 21.  9.]
merged = [12. 30. 42. 18.]

Example: Merge Two GroupWorkspaces

dataX = [1, 2, 3, 4, 5]
dataY = [6, 15, 21, 9]

a = CreateWorkspace(dataX, dataY)
b = CreateWorkspace(dataX, dataY)
c = CreateWorkspace(dataX, dataY)
d = CreateWorkspace(dataX, dataY)

group_1 = GroupWorkspaces(InputWorkspaces="a, b")
group_2 = GroupWorkspaces(InputWorkspaces="c, d")

merged = MergeRuns(InputWorkspaces="group_1, group_2")

print("group_1 = [{},".format(group_1[0].readY(0)))
print("           {}]".format(group_1[1].readY(0)))

print("group_2 = [{},".format(group_2[0].readY(0)))
print("           {}]".format(group_2[1].readY(0)))

print("merged   = {}".format(merged.readY(0)))

Output:

group_1 = [[ 6. 15. 21.  9.],
           [ 6. 15. 21.  9.]]
group_2 = [[ 6. 15. 21.  9.],
           [ 6. 15. 21.  9.]]
merged   = [24. 60. 84. 36.]

Note

To run these usage examples please first download the usage data, and add these to your path. In Mantid this is done using Manage User Directories.

Example: Merge Workspace Summing Sample Logs

Load(Filename='MUSR00015189.nxs, MUSR00015190.nxs', OutputWorkspace='gws')

merged = MergeRuns(InputWorkspaces='MUSR00015189_1, MUSR00015190_1',
                   SampleLogsSum='dur')

print(merged.run().getLogData('dur').value)

Output:

200.0

Example: Merge Workspace Combining Sample Logs as a TimeSeries

Load(Filename='MUSR00015189.nxs, MUSR00015190.nxs', OutputWorkspace='gws')

merged = MergeRuns(InputWorkspaces='MUSR00015189_1, MUSR00015190_1',
                   SampleLogsTimeSeries='sample_magn_field')

print(merged.run().getLogData('sample_magn_field').valueAsString().rstrip())

Output:

2007-Nov-27 17:10:35  1350
2007-Nov-27 17:12:30  1360

Example: Merge Workspace Combining Sample Logs as a List

Load(Filename='MUSR00015189.nxs, MUSR00015190.nxs', OutputWorkspace='gws')

merged = MergeRuns(InputWorkspaces='MUSR00015189_1, MUSR00015190_1',
                   SampleLogsList='sample_magn_field')

print(merged.run().getLogData('sample_magn_field').value)

Output:

1350, 1360

Example: Merge Workspace Combining Sample Logs with a Warnining if Different

Load(Filename='MUSR00015189.nxs, MUSR00015190.nxs', OutputWorkspace='gws')

merged = MergeRuns(InputWorkspaces='MUSR00015189_1, MUSR00015190_1',
                   SampleLogsTimeSeries='sample_temp',
                   SampleLogsWarn='sample_magn_field')

print(merged.run().getLogData('sample_temp').size())

Output:

2

Example: Merge Workspace Combining Sample Logs with an Error if Different

Load(Filename='MUSR00015189.nxs, MUSR00015190.nxs', OutputWorkspace='gws')

merged = MergeRuns(InputWorkspaces='MUSR00015189_1, MUSR00015190_1',
                   SampleLogsTimeSeries='sample_temp',
                   SampleLogsFail='sample_magn_field, nspectra',
                   SampleLogsFailTolerances='5, 0')

print(merged.run().getLogData('sample_temp').size())

Output:

1

Related Algorithms

ConjoinXRuns concatenates the workspaces in the x dimension by handling the merging of the Sample Logs. ConjoinWorkspaces combines workspaces by appending their spectra.

Categories: AlgorithmIndex | Transforms\Merging

Source

C++ header: MergeRuns.h

C++ source: MergeRuns.cpp