<d1b2>
<246tnt> How do I convert the I / Q channels into a complex channels to feed the FFT ?
<d1b2>
<246tnt> And aslo how do you delete a filter from teh filter graph editor ? Delete / Backspace doesn't work, can't see any option and I don't see anything about it in the user manual either.
<d1b2>
<azonenberg> Filters can't be deleted per se right now. Filters and channels are reference counted
<d1b2>
<azonenberg> They self delete when the last reference (downstream filter, measurement, waveform view, etc) goes away
<d1b2>
<azonenberg> if you've deleted the last waveform view (right click channel name, delete) and it didn't go away in the graph editor you've hit some kind of dangling reference bug
<d1b2>
<azonenberg> (this is going to get a major refactoring in the coming months, i've already completely revamped how we do ownership of instruments, but channels/filters are a bit more work)
<d1b2>
<azonenberg> You don't. We need to write a complex-input FFT filter still, this has been a pending TODO for some time
<d1b2>
<azonenberg> there is a complex input spectrogram filter already
<d1b2>
<azonenberg> (also, there is no "complex" channel type currently, we have separate I and Q streams you route in parallel)
<d1b2>
<azonenberg> The current FFT filter is intended to take scalar inputs
<d1b2>
<azonenberg> Generally speaking the SDR/RF filter suite is in its infancy, the UHD integration exists as a way to provide test signals but there isn't a whole lot you can do with them yet