Re: [Discuss-gnuradio] GRC filter tap evaluations - difference between current version and v 0.7

[Josh Blum]

It has to be evaluatable by the python parser.

map(lambda x: x/32768., [-23, 4, 245, 1235, 245, 4, -23])
or
numpy.array([-23, 4, 245, 1235, 245, 4, -23])/32768.

If you want to use the numpy, then make sure to include an import block 
with the line: import numpy

-Josh

Richard Clarke wrote:
> Hi All,
>
> With version 0.7 of GRC I could enter the taps of a filter in the following
> format [-23, 4, 245, 1235, 245, 4, -23]/32768 in the relevant GRC block
> window  (taps field) and GRC would do the division calculation for each tap,
> i.e the tap vector automatically became [-7.019e-4,1.22e-4, 7.47e-3,
> 3.76e-2, 7.47e-3, 1.22e-4, -7.019e-4].
>
> Trying to do the same thing in the current version of GRC that is included
> with GNU Radio 3.2rc2 results in a warning message that the tap vector
> cannot be evaluated. Does anyone know how to achieve the same thing as
> demonstrated above for version 0.7?
> A small thing I know but most coefficients of filters that I have come as
> fixed point 16 bit integers (-32768<=coeff<=32767) and doing a copy/paste is
> more convenient than doing the extra calculation and then formatting the
> resultant floating point vector into a copy and pasteable form for entry
> into the GRC blocks.
>
> Thanks very much.
>
> Cheers
> Richard
>
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio