Foton: Would Like a Way to Compute True Response of Filter from Filter File
This very likely comes from user misunderstanding, but the calibration group has run into issues modeling the response of foton filter designs when poles and zeros are close to the NyQuist frequency. For example, the first couple of slides in G1801581 cover the differences between
- a matlab model of a continuous filter, vs.
- a matlab model of a discrete filter made with the 'Tustin' approximation, vs.
- a foton export which has a different algorithm for pre-warping
We're no longer using matlab, but instead the scipy package in python to ingest the foton filter coefficients from the foton file, but (I think) there's still a difference between the python model of the filter from the coefficients and a export from foton.
We're hoping to not have to open up foton, make a bode plot, and export a text file in the future, and instead be able to make a model (in python) of the pre-warped filter's response.