On Sat, 2019-06-01 at 20:16 +0000, d.des wrote: > I want to add a phase shift block to a grc flowgraph that is > controlled > by a scrollbar. Searching for "phase shift block" returns several > suggestions from several years ago to use the "Multiply Const" block > with the argument: "math.cos(angle), math.sin(angle)" in the "const" > field. If I try that I get the error: > > Expression None is invalid for type 'complex'. > > I can enter fixed complex variables or references to other variables > or > parameters, I just can't do trig functions. I'm currently using the > equation: "pow(10,snr/20.)" in a Noise Source block and it > understands > that just fine. Is there a way to do trig functions in a block > field? > > I'm currently using a clean install and build of gnuradio retrieved > from git a few days ago, but this issue has been the case for the > several versions I've retrieved and built over the past year or so. I > ended up building a hier block with complex_to_magphase, add > constant, > and the magphase_to_complex but that seems very inefficient. The > transcendental function seems to be oriented to streams rather than > constants that rarely change. I also considered an OOT block but that > also seems like overkill. Surely I'm missing something really simple. > > > The expression should be: > > complex(math.cos(angle-in-radians),math.sin(angle-in-radians)) > > >This is standard Python stuff, not specifically related to GRC or > >Gnu Radio. > > >The assumption is that if you're going to be inserting Python > >expressions that those expressions > > are correct Python expressions.
I completely missed the import block. I don't speak Python and with grc I usually don't have to. Thanks! _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
