ryjobil there is one impulse every 128 samples with block size set to 128. It's possible to get better resolution, but I think it's adequate to see the shape of the filter. Btw this is shown on a linear scale because it's easier to see the shape that way.
This is for the devs - It would be cool if there was a setting for how lines are drawn (or not drawn) between points in the scope's fft mode. Also, settings for units, font size, etc would be useful.
I'm imagining these features as expansions to the scope class, and am interested in possibly developing these features along with a pole zero mapping utility in the form of a control system toolbox type package.
Is this something we could work on? I'm interested to hear what you think.