Compare photometric colors

[djperrefort]

PR #3 added a comparison of the color evolution for each CMFGEN model against DR3 photometry. Colors were determined for each DR3 target by interpolating in time with a gaussian regression. These values were then compared against the color evolution of each CMFGEN model. This work was a step in the right direction but was incomplete. Remaining steps include:

• The Gaussian regression can run away for phase values outside the observed phase range. The easiest way to fix this is to bound the Gaussian regression in each band between the first and last data point. (Finished in PR Compare photometric colors #6)

• The observed photometry suffers from extinction while the models do not. Extinction values for each target need to be looked up and applied to the models before comparison. These values are probably available on the Open Supernova Catalog. (Finished in PR Compare photometric colors #6)

• The error values returned by the Gaussian regression are too small. A "correct" (a word I use loosely) error implementation would involve resampling and looking at the variation in the Gaussian fits.

• This issue should culminate in a series of plots summarizing chi-squared values globally and band-by-band. We should plot chisquared distribution over all targets for two fixed phase ranges (-10 to 15 and something larger)

• We should also plot delta color over 15 days for the model vs the data.

• We are currently skipping targets without a CSP published t0 value or E(B-V) value. In the future, we can fit for and / or look up these values in other literature sources.