When using the BOT photodiode data to create the amp linearizers, there is a systematic error in the photodiode data that increases the residuals of the linearizer fit. Aaron Roodman has pointed out that the residuals are highly correlated across the focal plane, so by taking the mean (or median) of the residuals of all of the amps, we can create a correction to the photodiode reading that reduces the residuals. The attached plot shows that the reduction in the residuals is pretty dramatic. This ticket is for implementing that code within the existing framework.