On Wed, May 13, 2009 at 03:40:31PM -0400, Marcus D. Leech wrote: > I don't understand why this is failing: > > Traceback (most recent call last): > File "./top_block.py", line 184, in <module> > tb = top_block(options) > File "./top_block.py", line 97, in __init__ > 1, bw, -7.0, 7.0, 150, firdes.WIN_HAMMING, 6.76)) > File > "/usr/local/lib/python2.5/site-packages/gnuradio/gr/gnuradio_swig_py_general.py", > line 2729, in band_pass > return _gnuradio_swig_py_general.firdes_band_pass(*args, **kwargs) > IndexError: gr_firdes check failed: 0 < fa <= sampling_freq / 2 > > > When I specify negative frequencies, it does this. > > I thought that with a complex filter, I could specify negative frequency? > > This particular filter is a decimating filter that is decminating from > 500KHz sample rate down to 32KHz sample rate, > with cutoff between -7KHz and +7KHz. But I'm triggering this error, > and I don't understand why. This is from > a GRC flow-graph. >
Just use a low pass (0 .. 7k). No need for the bandpass. firdes_band_pass (and the lowpass for that matter) design real filters coeffs that you can use with gr.fir_filter_ccf. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
