It’s counter to the experience with the regular dot-product FIR filters
in that you can re-size them at runtime and it’s just fine. It
certainly fails the
“least astonishment” test when you have a filter that’s configured
for “pass-through” (1+0j single tap) and then later ask it to do some
But this bug has been around for a long time, as I was reminded. My
other code has “hacks” to get around this, and when I was re-structuring
for migration to GR3.7, it reared its unpleasant little head again.
Granted, my use case, in this case, is a bit weird–the filter can go
from “passthrough” to “farking massive” in one swell foop, when the user
turns on coherent dedispersion and suddenly that’s a rather-large
de-dispersion filter in the path.
Shirleys Bay Radio Astronomy Consortium