dQ data is not handled properly when loaded from CanSAS1D and NXcanSAS

[smk78]

The ISIS SANS interface in Mantid now permits the calculation of Qres (dQ) data which can then be written to CanSAS1D XML or NXcanSAS. In testing compatibility with SasView I have observed the following:

Loading from CanSAS1D:

SasView 4.0.1 - works fine! On selecting a model and checking Use dQ Data the dQ data range is displayed. Fitting proceeds ok.

SasView 4.1 local build - On opening a file containing dQ data SasView throws the error:

2016-12-15 15:48:45 : The following errors occured whilst loading
41951_1D_qres.xml:
Error:
The loaded xml file, 41951_1D_qres.xml does not fully meet the CanSAS
v1.x specification. SasView loaded as much of the data as possible.
Element '{urn:cansas1d:1.1}name': This element is not expected.
Expected is one of ( {urn:cansas1d:1.1}length,
{urn:cansas1d:1.1}aperture )., line 136

The data is still read and can be sent to fitting but the dQ data is not available.

Loading from NXcanSAS:

SasView 4.0.1 - The data is read and can be sent to fitting but the dQ data is not available to SasView.

SasView 4.1 local build - The data is read and can be sent to fitting but the dQ data is not available to SasView.

[smk78]

CanSAS1D without dQ values

[smk78]

CanSAS1D with dQ values

[smk78]

NXcanSAS without dQ values

[smk78]

NXcanSAS with dQ values

[krzywon]

Looking at the XML data you have given, it seems the <SASCollimation> entry is not to the CanSAS v1.1 standard. The <name>, <X>, and <Y> elements should be held within an <aperture> element but are directly within <SASCollimation>. I've modified the reader since the release of 4.0.1 to display XML errors when they are found, so not displaying the error before was a bug.

The SasView HDF reader is not reading in the Qdev data. I'll get a fix in today.

[krzywon]

In bbd0f37aa83b3764868742835a730122ba826585/sasview:

#826: CanSAS HDF5 reader reads in the Qdev data now.

[krzywon]

Rereading the original note, the handling of dQ data from the XML is not right. I'm looking into it.

[krzywon]

In 67b0a99ce9f69a9dfef035e8e4a06588c9f1602f/sasview:

#761: Constrained fit pages are now deleted if they no longer have any data in them when other data sets are deleted. #826: Fixed a bug where dQ smearing option was unavailable for 1D data sets.

[krzywon]

This should be fixed as of the latest build on Jenkins. Please test and confirm the dQ is handled properly for both the XML and HDF5 CanSAS data.

[smk78]

Have just pulled and built SasView locally, and downloaded Jenkins build 621. Both versions LOAD the XML and H5 datasets but DO NOT appear to use the dQ data - although the 'Use dQ' radio button is checked, no dQ values appear in the FitPage.

[krzywon]

In 24fd27a2f35f316c4971c10c5c3a317dd9357597/sasview:

#826: Smearing should now be applied to 1D data with dQ data present. This was an issue for all 1D data.

[krzywon]

A fix for this is now in master and should be tested when possible.

[smk78]

Pulled and built on Win7.

XML & H5 datasets load and can be fitted. Use dQ is automatically selected and fitting with it enabled does generate a slightly better fit than if it is not enabled.

However, loading the XML still throws the error in the original ticket. But you can OK and continue.

[krzywon]

The XML loading error won't be going away. The XML files attached to this ticket do not meet the CanSAS specification which is where this error message is coming from. I mentioned the issue with them in comment2. It seems wherever these files are from (Mantid?), the <SAScollimation> element is not being generated properly.

[smk78]

Mantid team will endeavour to fix the CanSAS1D XML issue for v3.9.0 in Feb.