# Error trying to load taps into FFT filter

**URL:** <https://www.ruby-forum.com/t/error-trying-to-load-taps-into-fft-filter/240540>\
**Category:** GNU Radio\
**Created:** [April 19, 2014, 6:37pm UTC](https://www.ruby-forum.com/t/error-trying-to-load-taps-into-fft-filter/240540 "2014-04-19T18:37:16Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\
**Post date:** [April 19, 2014, 6:37pm UTC](https://www.ruby-forum.com/t/error-trying-to-load-taps-into-fft-filter/240540/1 "2014-04-19T18:37:16Z")

</div>

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  
  
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 &’