Ticket #3285 (closed: invalid)
DiffractionFocussing support for Q Histogram v event differences
| Reported by: | Nick Draper | Owned by: | Nick Draper |
|---|---|---|---|
| Priority: | major | Milestone: | Release 2.5 |
| Component: | Mantid | Keywords: | |
| Cc: | Blocked By: | ||
| Blocking: | Tester: |
Description
The following scripts shows a fairly significant difference between the Workspace2D and event versions of the algorithm:
# 2D version
LoadEventNexus(Filename="/home/8oz/data/PG3_1370_event.nxs",OutputWorkspace="pg3",CompressTolerance="0.050000000000000003")
ConvertUnits(InputWorkspace="pg3",OutputWorkspace="pg3",Target="MomentumTransfer")
Rebin(InputWorkspace="pg3",OutputWorkspace="pg3",Params="0,1,40")
CreateGroupingWorkspace(InstrumentName="PG3",GroupNames="bank124,bank144,bank164,bank184",OutputWorkspace="pg3_group")
ConvertToMatrixWorkspace(InputWorkspace="pg3",OutputWorkspace="pg32d")
DiffractionFocussing(InputWorkspace="pg32d",OutputWorkspace="pg3_foc_2d",GroupingWorkspace="pg3_group")
# Event version
CreateGroupingWorkspace(InstrumentName="PG3",GroupNames="bank124,bank144,bank164,bank184",OutputWorkspace="pg3_group")
DiffractionFocussing(InputWorkspace="pg3",OutputWorkspace="pg3_foc",GroupingWorkspace="pg3_group")
Minus("pg3_foc", "pg3_foc_2d", "pg3_diff")
If you compare pg3_foc and pg3_foc_2d on a plot, they look pretty different. I'm not sure if this is specific to Q; or if it has something to do with Martyn's "fixes" to spectrum numbers.
Attachments
Change History
comment:3 Changed 9 years ago by Wenduo Zhou
According to some tests that I've done, here are some conclusion drawn from the observation.
- The different result between MatrixWorkspace and EventWorkspace is not specific in Q. If the units are converted to d-spacing before DiffractionFocussing(), there is difference in the resulted MatrixWorkspace and EventWorkspace still. (Referring to attached errorcheckind.py and errorcheckinq.py)
- If "PreserveEvent", one of DiffractionFocusing's inputs, is chosen to be False, then there is no difference between the results (EventWorkspace vs. MatrixWorkspace). Therefore, the disparity should be rooted from the inconsistency between the algorithms to treat MatrixWorkspace data and events.
comment:4 Changed 9 years ago by Wenduo Zhou
If the Workspaces are rebinned in a reasonable resolution, the difference between the results of DiffractionFocussing done in MatrixWorkspace and EventWorkspace is trivial. Please refer to attached two .png files.
comment:5 Changed 9 years ago by Wenduo Zhou
- Status changed from accepted to assigned
- Owner changed from Wenduo Zhou to Nick Draper
comment:6 Changed 9 years ago by Nick Draper
- Milestone changed from Iteration 30 to Iteration 31
Bulk move of tickets to iteration 31 at the iteration 30 code freeze
comment:7 Changed 9 years ago by Nick Draper
- Milestone changed from Iteration 32 to Iteration 33
Moved to iteration 33 at iteration 32 code freeze
comment:8 Changed 8 years ago by Nick Draper
- Milestone changed from Release 2.1 to Release 2.2
Moved at end of release 2.1
comment:9 Changed 8 years ago by Nick Draper
- Milestone changed from Release 2.2 to Release 2.3
Moved at the end of release 2.2
comment:10 Changed 8 years ago by Nick Draper
- Milestone changed from Release 2.3 to Release 2.4
Moved to milestone 2.4
comment:12 Changed 8 years ago by Nick Draper
- Status changed from assigned to accepted
The differences seem minor, worksforme
comment:13 Changed 8 years ago by Nick Draper
- Status changed from accepted to verify
- Resolution set to worksforme
comment:14 Changed 8 years ago by Nick Draper
test
comment:15 Changed 8 years ago by Nick Draper
- Status changed from verify to closed
- Resolution changed from worksforme to invalid
closed
comment:16 Changed 5 years ago by Stuart Campbell
This ticket has been transferred to github issue 4132
See issue raised by Janik #3065