Ticket #8624 (closed: fixed)
Extent and increase the sampling density of the time domain in the StretchedExFT fitting function
Reported by: | Jose Borreguero | Owned by: | Jose Borreguero |
---|---|---|---|
Priority: | major | Milestone: | Release 3.1 |
Component: | Indirect Inelastic | Keywords: | |
Cc: | Blocked By: | ||
Blocking: | Tester: | Roman Tolchenov |
Description (last modified by Jose Borreguero) (diff)
The StretchedExFT fitting function calculates the FFT of the stretched exponential using as many time points as bins in the histogram data. This turns out to be insufficient. Many more time points are neccessary to produce a Fourier Transform that can be fitted to the data.
Note to TESTER:
Donwload all attachments and open the python script in the script window of MantidPlot. The header of the script contains the instructions to test the ticket. (the png files are there if you want to take a look at the "experimental" structure factors to be fitted) You can modify the initial guesses for the fitting parameters to see how robust is the fit with respect to the initial guess.
Attachments
Change History
Changed 7 years ago by Jose Borreguero
- Attachment lorentzian1.dat added
Changed 7 years ago by Jose Borreguero
- Attachment lorentzian1.png added
lorentzian structure factor plot
Changed 7 years ago by Jose Borreguero
- Attachment gaussian1.dat added
gaussian structure factor data
Changed 7 years ago by Jose Borreguero
- Attachment gaussian1.png added
gaussian structure factor plot
Changed 7 years ago by Jose Borreguero
- Attachment test_ticket_8624.py added
do fits to lorentzian and gaussian
comment:1 Changed 7 years ago by Jose Borreguero
- Status changed from new to inprogress
Refs #8624 improved time domain
both tmin and tmax have been extended to make sure we obtain a sufficiently complete frequency spectrum after doing the fourier transform
modified: StretchedExpFT.py modified: StretchedExpFTTest.py
Changeset: 54c3fefe2e922797bafde3254c78816bec2147ef
comment:2 Changed 7 years ago by Jose Borreguero
Refs #8624 Impose limit on time domain size
Extension of the time domain may create a too large one, thus lengthening the fitting in excess
modified: StretchedExpFT.py modified: StretchedExpFTTest.py
Changeset: 7be194d98f1877296c84f17945947134e786f27a
comment:4 Changed 7 years ago by Jose Borreguero
Note to TESTER: please read the tester notes in the Description of the ticket
comment:5 Changed 7 years ago by Jose Borreguero
- Status changed from inprogress to verify
- Resolution set to fixed
comment:6 Changed 7 years ago by Jose Borreguero
Notes to tester: Please read the notes for the tester in the description of the ticket
comment:7 Changed 7 years ago by Roman Tolchenov
- Status changed from verify to verifying
- Tester set to Roman Tolchenov
comment:8 Changed 7 years ago by Roman Tolchenov
- Status changed from verifying to closed
Changes make fit better.
comment:9 Changed 7 years ago by Roman Tolchenov
Merge remote-tracking branch 'origin/feature/8624_improve_time_sampling_stExFT'
Full changeset: 2168e72cb610cb6279f253abae2a8ab3dd631a74
comment:10 Changed 7 years ago by Jose Borreguero
- Component changed from Framework to Indirect Inelastic
comment:11 Changed 5 years ago by Stuart Campbell
This ticket has been transferred to github issue 9468
lorentzian strutcture factor data