Re: [Discuss-gnuradio] Error trying to load FFT filter taps

[Tom Rondeau]

On Sat, Apr 19, 2014 at 1:27 PM, Tom McDermott <address@hidden> wrote:

Am getting the following error when trying to run a GRC flowgraph that loads FFT filter taps from an external file. The type filter parameter is set to complex->complex (complex taps).

The flow graph has imported numpy.  The taps are loaded using:

numpy.fromfile('/home/tom/Desktop/EchoScreencaps/chirp-down-20-20-131072', numpy.complex64)

as the taps parameter.  What does the error below mean?

GRC: v3.7.4git-101-g76970d54

Ubuntu 13.10

top_block.py is attached.

-- Tom, N5EG

Traceback (most recent call last):
  File "/home/tom/Desktop/EchoScreencaps/top_block.py", line 173, in <module>
    tb = top_block()
  File "/home/tom/Desktop/EchoScreencaps/top_block.py", line 115, in __init__
    self.fft_filter_xxx_0 = filter.fft_filter_ccc(1, (numpy.fromfile('/home/tom/Desktop/EchoScreencaps/chirp-down-20-20-131072', numpy.complex64)), 1)
  File "/usr/local/lib/python2.7/dist-packages/gnuradio/filter/filter_swig.py", line 1329, in make
    return _filter_swig.fft_filter_ccc_make(*args, **kwargs)
TypeError: in method 'fft_filter_ccc_make', argument 2 of type 'std::vector< gr_complex,std::allocator< gr_complex > > const &'

Tom,

This is a conflict between the numpy array data type and swig. Call the .tolist() function on the array passed back from numpy and it should work.

Tom