Timeline for IIR to FIR, is a best fit polynomial usually necessary?
Current License: CC BY-SA 4.0
16 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 2, 2020 at 7:49 | answer | added | robert bristow-johnson | timeline score: 1 | |
| Aug 2, 2020 at 5:28 | history | edited | robert bristow-johnson | CC BY-SA 4.0 |
i think that's the current conventional notation for the impulse response h[n].
|
| Aug 1, 2020 at 19:07 | comment | added | Cedron Dawg | @MattL. That would be cheating. I'll look when I got this figured out, then compare. Thanks for the link, I'll remember where it is. | |
| Aug 1, 2020 at 18:58 | comment | added | Matt L. | Have you seen this answer explaining how to obtain IIR filter coefficients from given input and output sequences? | |
| Aug 1, 2020 at 16:50 | comment | added | Cedron Dawg | ... and a's and b's "swap values" for a better local fit. I think I need to ensure wider bandwidth in by test signal. I can also find and exact FIR fit for a FIR filter, but I don't think that is anything special. Neither might my IIR technique be. | |
| Aug 1, 2020 at 16:46 | comment | added | Cedron Dawg | Yes, my question concerns a subset of my problem. I should be able to convert back and forth between a best fit IIR and a best fit FIR. My initial inclination was IIR->FIR easy, FIR->IIR hard, then I found the link and the IIR->FIR was made harder by the order constraint. I'm just trying to get an idea of the landscape of the arena I am in. I have heard of "thousands of FIR coefficients before", confirmed again by Hilmar. A truncated FIR->IIR is going to be harder than a longer one I would think. Numerically I can find a best fit IIR, exactly with the right rank set, but more freedom... | |
| Aug 1, 2020 at 16:36 | comment | added | Matt L. | I'm a bit confused at your problem statement. In the above question you seem to be looking for a way to approximate a given IIR filter by an FIR filter. In your comment under Hilmar's answer, you seem to be looking for an IIR filter that produces a given output sequence from a given input sequence. Those two problems are different, aren't they? | |
| Aug 1, 2020 at 14:35 | history | edited | Cedron Dawg | CC BY-SA 4.0 |
added 30 characters in body
|
| Aug 1, 2020 at 13:51 | answer | added | Olli Niemitalo | timeline score: 2 | |
| Aug 1, 2020 at 13:28 | history | edited | Gilles | CC BY-SA 4.0 |
improved formatting
|
| Aug 1, 2020 at 13:10 | answer | added | Hilmar | timeline score: 1 | |
| Aug 1, 2020 at 12:32 | history | edited | Cedron Dawg | CC BY-SA 4.0 |
edited body
|
| Aug 1, 2020 at 12:25 | history | edited | Cedron Dawg | CC BY-SA 4.0 |
added 498 characters in body
|
| Aug 1, 2020 at 10:57 | comment | added | Cedron Dawg | @MattL. Thanks Matt. I am actually working on the general X case, not just an impulse, so this is a special case, but good to know and I'll include it. I figured if I can find the exact IIR to any X and Y then I can find a corresponding FIR, so full solution, compact IIR or extended FIR. In the process, I wanted to confirm the principle illustrated in my question, and couldn't find a polynomial (we used to call it synthetic division) routine. I thought that odd. So now it turns out if I can find any IIR in general I can also solve the best fit IIR to any FIR. Correct? | |
| Aug 1, 2020 at 8:01 | comment | added | Matt L. | I think scipy.signal.dimpulse is what you're looking for. | |
| Aug 1, 2020 at 2:47 | history | asked | Cedron Dawg | CC BY-SA 4.0 |