Sum|Multiply loses or mislabels parameters in plugin models created with plugins in 4.2.2

[smk78]

Using 4.2.2 on W10/x64

User Matt Potter noticed that when building a plugin model from other plugin models using Sum|Multiply, sometimes the individual model parameter identifier (eg, A, B, etc) was being applied to parameters from the wrong model.

In trying to replicate this behaviour, I discovered that some model parameters got totally omitted!

However, if you manually edit the plugin file so that you are not using plugin model names, all is well.

To reproduce:

• Run 4.2.2
• Fitting > Plugin Model Operations> Sum|Multi(p1,p2)
• Give a function name (zzz)
• Enter a description (gaussian_plus_gaussian)
• Select model_1 as gaussian_peak
• Select model_2 as gaussian_peak
• Select + and Apply and Close
• To be certain SasView knows about the new plugin (it should happen automatically though) do Fitting > Plugin Model Operations> Load Plugin Models

A valid plugin is created:

from sasmodels.core import load_model_info
from sasmodels.sasview_model import make_model_from_info

model_info = load_model_info('gaussian_peak+gaussian_peak')
model_info.name = 'zzz'
model_info.description = 'gauss_plus_gauss'
Model = make_model_from_info(model_info)

Now build on that plugin:

• Fitting > Plugin Model Operations> Sum|Multi(p1,p2)
• Give a function name (zzzz)
• Enter a description (zzz_plus_power)
• Select model_1 as zzz
• Select model_2 as power_law
• Select + and Apply and Close
• Fitting > Plugin Model Operations> Load Plugin Models

A valid plugin is created:

from sasmodels.core import load_model_info
from sasmodels.sasview_model import make_model_from_info

model_info = load_model_info('zzz+power_law')
model_info.name = 'zzzz'
model_info.description = 'zzz_plus_power'
Model = make_model_from_info(model_info)

Now build on that plugin:

• Fitting > Plugin Model Operations> Sum|Multi(p1,p2)
• Give a function name (zzzzz)
• Enter a description (zzzz_plus_fractal)
• Select model_1 as zzzz
• Select model_2 as fractal
• Select + and Apply and Close
• Fitting > Plugin Model Operations> Load Plugin Models

A valid plugin is created:

from sasmodels.core import load_model_info
from sasmodels.sasview_model import make_model_from_info

model_info = load_model_info('zzzz+fractal')
model_info.name = 'zzzzz'
model_info.description = 'zzzz_plus_fractal'
Model = make_model_from_info(model_info)

All three plugins can be loaded into a FitPage

Now go to .sasview\plugin_models and make a copy of one of the plugins.

• rename the file (zzzzzz.py)
• edit the file to look like this:

from sasmodels.core import load_model_info
from sasmodels.sasview_model import make_model_from_info

model_info = load_model_info('gaussian_peak+gaussian_peak+power_law+fractal')
model_info.name = 'zzzzzz'
model_info.description = 'the-lot'
Model = make_model_from_info(model_info)

Create two FitPages and load plugin zzzzz into one of them:

and load plugin zzzzzz into the other:

Notice that:

• in the zzzzz (1st) case, only 3 model contributions are identified (A, B and C_)
• in the zzzzz (1st case), the parameter A_sigma is absent!

Whereas the zzzzzz (2nd) case is the expected - and correct!!! - result.

[smk78]

Also see https://github.com/SasView/sasview/issues/1451

[smk78]

4.x fitting_help modified as per changes made to 5.x fitting_help (see https://github.com/SasView/sasview/issues/1451)

[butlerpd]

I note that in another ticket, @pkienzle suggests we don't need the two make_model_from_info lines in the mixture models above. Not sure if that is causing part of the problem? but doubt it. As I understand it however the deeper problem is buried in sasmodels and not a quick fix. I am therefore going to move this to the graveyard pile (there being other relevant issues for 5.x) for now.