Timeline for IIR to FIR, is a best fit polynomial usually necessary?
Current License: CC BY-SA 4.0
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| Aug 1, 2020 at 16:39 | comment | added | Cedron Dawg | I'm trying to solve the opposite black box problem. Given a stretch of the input and and corresponding output of a filter, figure out whether it is IIR or FIR and what the coefficients are. These considerations are part of that, real life parameters will give me targets to test against. So, first I have to generate some ideal noiseless inputs and outputs to work against. The above code is part of that. There can be noise in the signals, vs noise in my data collection for real data. | |
| Aug 1, 2020 at 16:24 | comment | added | Hilmar | In my experience you never use a middle man. If you want FIR you design this directly, if you want IIR, you design that directly. There is an interesting middle ground: "Warped FIR" it's an IIR but can be designed using FIR design methods in a "warped" frequency domain. | |
| Aug 1, 2020 at 13:35 | comment | added | Cedron Dawg | Thanks, I am trying to "cut out the middle man" in the other direction, wondering if it had any practical value and the dimensions of real life systems. Suppose a system is governed by an unknown IIR. My shallow understanding (just starting to explore) is that the usual procedure is to find a FIR (H(z)) then use methods to derive the best fit IIR (A(z) and B(z)). I set about trying to find the best IIR directly from an arbitrary input and it's corresponding output. Some success so far. The polynomial division is part of a double check. | |
| Aug 1, 2020 at 13:10 | history | answered | Hilmar | CC BY-SA 4.0 |