Ideas for the demo

[JeffValenti]

• Demonstrate simple fitting functions (1 or 2 gaussians with and without noise). Compare results with known inputs and results from MPFIT in IDL.
• Demonstrate implementation of Jerry's much more complicated specfit example, including reddening but not Gaussian skew. Compare with known inputs and results from specfit.
• Demonstrate adding a user-defined function, in this case reddening in Jerry's original example. Reddening code will come from pysynphot.
• Time permitting, demonstrate parameter tying, as in Jerry's specfit example
• Present and discuss different approaches for handling model and fitting parameters in disk files and as python objects.
• Defer other topics: LSF convolution, model resampling.