CodeCampIII_ScheduleAndWork_SasModelsWP

SasModels Redesign Tasks

#90Provide a way for plugin models to use the built-in polydispersity functions#91Port models to C++ from python#251Create new default category list#294Refactor Model Interface#312Problem with slit smearing#313Python polydispersity#314Default to GPU when using OpenCL#315Be able to set choice of device for OpenCL[#316](/ticket/316 "Autogenerate sasmodel "shims"")Autogenerate sasmodel "shims"#317Packaging of sasmodels (build scripts etc)#319sasmodels unit testing#330allow inf/-inf for model limits#359Be able to use new models from sasmodels alongside sas.models models#361Check all models for order of parameters being passed#363break OpenCL calculations into smaller chunks.#399GelFit model presents an erroneous parameter#400DAB model equation in model function help file is wrongPorod model equation in model function help file is wrongreparameterize Teubner-Strey#476autogenerate theory curves for sasmodels documentation#484lamellarPC is precision limited#499create sin(x)/x, 2*J1(x)/x and 3*j1(x)/x functions#504Convert model editors to support sasmodels#505List modules needing changing to accommodate sasmodels new structure#506Fix loading of models in models.py and autodiscovery#524category handling needs updating for sasmodels#525Add GUI category defaults to models in sasmodels#530Numerical instabilities in Teubner Strey model#532Handling of custom models via sasmodels#533Make polydispersy work in sasview with sasmodels#534Fitting not working in sasview with sasmodels#536Add multiplicity model infrastructure to sasmodels#537Magnetic sld not implemented for python models#538Need to clean out old sasmodels infrastructure from SasView#539build servers to build working windows exe#540build servers to build working mac SasView 4.0 dmg#543control order in which fit parameters appear in gui for easy sum/multi models#544control order in which fit parameters appear in gui for user supplied models#548Remove MutiplicationModel.py once replacement from Sasmodels is available#650Standardize C model names#675Reparameterize hollow_cylinder#695linear slope in onion model#775Orientation of stacked_discs model does not work#776angular dispersity#890use new orientation definition for asymmetric shapes#891update docs for oriented shapes with new orientation definition#896equations in core shell parallelepiped docs do not match code#1046convert non builtin models in the marketplace to new API

Practicalities

The list of (non)overlapping SasView-SASfit models can be viewed at: ​https://ess-ics.atlassian.net/wiki/display/SAS/SasView-SasFit+Overlapping+Models

OpenCL test results for various OS-GPU combinations.

Instructions for converting models from old SasView to sasmodels

List of models for conversion

SasModels package code is here: ​http://github.com/SasView/sasmodels

SasView code is here: ​http://github.com/SasView/sasview

Preconverted latex (top and bottom of the file, missing some in the middle): ​http://sasview.org/attachment/wiki/SasModels%20Work%20Package/Equations.docx.pdf

Options for Angstrom symbol:

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• \text{A}
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• \text{nm}/10

Work Plan/Tasks/Ideas

Level 1

• Python Polydispersity - Paul - #313
• Default to GPU when using OpenCL - David - #314
• Be able to set choice of device for OpenCL - David - #315
• Autogenerate sasmodel "shims" - Andrew - [#316](http://trac.sasview.org/ticket/316 "defect: Autogenerate sasmodel "shims" (closed: wontfix)")
• Packaging of sasmodels (build scripts etc) - Andrew - #317
  • Integration of sasmodels documentation with SasView? - Peter? - #318
  • Build scripts for sasmodels package
• sasmodels unittest - Paul K? or Peter? - #319

Level 2

• Migrate models - need a checklist and progress tracking for this
  • Magnetic models
  • Make "template" for a model
  • Make "standard" list of parameter names
  • Define attributes on model (form factor, structure factor, multiplicity etc)
  • Move model details to python part (parameters, docs)
  • Move scattering kernel to c part
  • Unit tests
  • Documentation
• Model discovery in sasview
• Move dataloader

Level 3

• Refactor models interface
  • Attributes
  • Extra data on models
• Resolution calculation in python
• Constraints in polydispersity loop
• Refactor data structures (including 4 cross-section magnetic 2D)
• Complex scattering lengths
• Make "simple model" system in sasview add a model in the new style

---

• Start from P Kienzle sasmodels work - fork sasmodels
• Refactor of sasview to use new package
• How to deal with model categorisation
• Cross validate against existing sas.models
• Polydispersity for python models

Issues

• Normalization
• PqSq
• Single vs double
• Make sure model is rebuilt if c changes

Work Package Description (From Google Docs)

Simplify addition of new models

Statement of Problem to address:

Currently addition of a new model in C requires a rebuilding of the SasView GUI application. Furthermore it requires the creation/editing of a lot of different files and is anything but straightforward making the learning curve quite steep. Finally, while a user can simply add a custom python model, that model does not have access to the necessary polydispersity calculation. Also not clear how the python model code can call a C model (to enhance for example). Making the addition of a C model simple and allowing python model to work properly with polydispersity would have a HUGE impact. New models are probably the single most important thing for the user community and with this change model addition can be removed from the core developer group tasks to being something instrument scientists and power user can do.

This is mostly an underlying computational framework project but also requires tying into existing GUI.

Goal/scope of project: Define and implement a clean C plugin interface that allows dropping a new C based model onto disk that can be discovered live by SasView. If at all possible allow python models to have access to polydispersity code.

Design Requirements:

• Adding a new model in C (for speed) should consist of writing only one file and may possibly require compiling of the model into a shared library file (how does one handle multiple platforms?) (Should !asView compile the models?)
• Adding a new model in C or python consists of dropping the appropriate file into the models directory for discovery by the running application (not GUI bits at this point --- applications can send to GUI bits)
• GUI must update available models while running
• Polydispersity treated properly for constrained/simultaneous
• Accessible Attributes for S(Q), multiplicity, etc
• Compatible with multiprocessing
• Minor requirement
  • All models should be treated the same (custom, python, "built-in" etc.)
• Optional requirement
  • Would also be nice if python models can access polydispersity

Tasks:

• Come up with and propose design that meets these needs with minimum "intrusion"
• Document Tasks required to achieve full integration with above design - should be at a level that a new person could take on the tasks including code snippets as necessary.
• Decision
• Implementation
• Refactor model code as per design above
• Create/write discovery process in SasView fitting so that computational code updates list of known models to use in fitting
• Create link to SasView GUI so that GUI also updates models available to GUI users while running