question for theorists: zeros & phase

[Martin Czech]

:::At work I have this picture stuck up in my room. The picture is from Bob Pease
:::"Troubleshooting Analog Circuits". It's a Ziggy strip with a man visiting his
:::doctor with a larchis animal chewing on his foot while the doctor concerned
:::says "I'll have to run some tests, but I'm pretty sure that it's either an
:::alligator or a crocodile." (the viewer can see the same). The point is, some
:::things are not worth analysing further, since it doesn't help you in the
:::problemsolving (in this case actually remove the alligator/crocodile from
:::the poor mans leg). I think it applies as well to your phase trouble.

No, not quite. It's about testcases I wanted to use for my little program.
Then the question arrises: what is the "real" phase response, and is
the computed somwhat similar?

That's when the trouble started.

And, after all, FIR filters actually have some of their zeros planned
to be on the unit circle.  All poles of a continous system get one zero
on the unit circle at PI when doing bilinear transformation.

They may get a bit off side due to parameter resolution.

So , when you try to design something you try to test it afterwards, and it would
be nice to know how things should be (with theoretical values).

m.c.