/Common Data Format
From canSAS
Detailed notes group (?):
- (repeated in Multiple Scattering Discussion):
- The package approach in BA might cause issues while SASview does not have them. Once the interface is defined it is hard to change it, same for the file format. One can design them to be extensible (NEXUS), to use new features. One has to think carefully what you insist people provide. For SAS data format, reflection format you need to provide certain information. The idea was that it can be extensible and if information is not provided it is simply skipped.
- canSAS XML was developed for this. But people don’t use it in a right way, they don’t fill out the fields, data has incorrect format. It is not easy to solve these problems.
- The challenge with BA is that we don’t understand what is the input data. Originally was built around a monochromatic instrument with cartesian coordinates around the scattered beam. Strictly speaking SASview works in q space and it doesn’t assume anything about the detector space.
- One of the differences is how to make the software instrument independent. SASview: you provide reduced data where you have taken out all the instrument effects. The idea of q resolution without WL and angle, it can accommodate data from instruments with multiple detectors, you can concatenate them in one file.
- Before software for SAS used to compare errors if you have an area detector there are many pixels that goes to the same bin. What is the variation pix to pix in there. Statistics over the individual pixels is compared with the variation. One needs to have more information to test that. When it comes to model fitting you don’t trouble the fitting program with too complicated procedure at the moment. The peak fitting for diffraction already causes people a lot of problems. Once you try to correct for more things you get more uncertainties.
- With GISANS you re not obliged to throw away the original raw counts. Whether software can handle? The motivation for having a reduced dataset is to have data format that is transferable between softwares. But have you thrown too much at some point?
- The package approach in BA might cause issues while SASview does not have them. Once the interface is defined it is hard to change it, same for the file format. One can design them to be extensible (NEXUS), to use new features. One has to think carefully what you insist people provide. For SAS data format, reflection format you need to provide certain information. The idea was that it can be extensible and if information is not provided it is simply skipped.
