Frequently Asked Questions

Here are the answers to some common questions about SasView:

What is SasView?

What platforms does SasView run on?

Do I need to install Python/C++ or any compilers before I install SasView?

Can SasView make use of my GPU(s)?

Can I stop SasView trying to use my GPU(s)?

Can I use SasView to analyse SANS/USANS data?

Can I use SasView to analyse SAXS/USAXS data?

Can SasView be used in a commercial environment?

What format should my data be in?

What units should my data be in?

Does SasView fit data in its I vs Q representation, or as Log I vs Log Q?

Many models have a scale parameter; what is this?

How can I put my data on an absolute intensity scale?

Why do I get non-sensical parameter values if I try to simultaneously model-fit the scale factor and the scattering length densities?

What value should I use to specify polydispersity?

Is the Schulz(-Zimm) polydispersity function used in SasView a number-average or a weight-average distribution?

What about the other polydispersity functions used in SasView?

How do I load an image file as data?

Where do the model parameter uncertainties come from?

Why do I get different parameter uncertainties using the Simple and Complex fitting engines?

Why do I sometimes get different 'goodness-of-fit' values when pressing Enter or Compute compared to pressing Fit?

Why have I got several instances of the same model category (eg, 'Shape Independent' and 'Shape-Independent')?

Why is SasView not loading the model parameters from some of my existing .fitv (Save Fit) files?

Why is Save Analysis (File menu) greyed out after I fit a model?

Why doesn't Check for Updates work?

Why is SasView no longer able to run my existing custom models?

How can I see the separate contributions of the form factor and structure factor?

How can I include a structure factor in a model?

What is the Model Marketplace?