GNU Radio filter design tool (gr_filter_design)
Question: I am having some trouble getting the filter design tool to even start. When
starting the application I get

    
    
    "This example requires a Numerical Python Extension, but
     failed to import either NumPy, or numarray, or Numeric.
     NumPy is available at http://sourceforge.net/projects/numpy". 
    

I have rebuild GNU Radio a couple of times now, and I am fairly sure that I
have every thing installed that is required. I do have numpy installed, and I
have tried a couple of versions just to be safe.

Has some one else had this problem?


Answer: You are getting this error as

    
    
    from PyQt4.Qwt5.anynumpy import * 
    

in polezero_plot.py (/usr/lib/python2.7/site-packages/gnuradio/filter) is
failing.

Just try replacing

    
    
    from PyQt4.Qwt5.anynumpy import * ( line no 25) 
    

with

    
    
    from scipy import zeros 
    

or

    
    
    from numpy import zeros
    

