Re: GRC Filter Taps read from file. (3.8.2.0 - from source)

[David Taylor (manx.net)]

Marcus, Jeff,

The files were simply not being recognised. A combination of path and format/ endianess.

Now working with both space de-limited text as per Jeff’s example and numpy.float32 files as source.

Many thanks.

 

David

 

From: Jeff Long

Sent: Wednesday, September 16, 2020 9:14 PM

To: GNURadio Discussion List

Subject: Re: GRC Filter Taps read from file. (3.8.2.0 - from source)

 

This works for me ... add an import block with "import numpy as np" ... for taps use "np.genfromtxt('/tmp/taps.txt')" where the file contains a space-delimited set of values.

 

On Wed, Sep 16, 2020 at 1:23 PM Marcus D. Leech <patchvonbraun@gmail.com> wrote:

On 09/16/2020 01:10 PM, David Taylor (manx.net) wrote:

Hi,

 

I am trying to import a large number of taps (1023) into a Decimating FIR Filter, in order to repeat (as reference), a GRC experiment that was published about four years ago.

The taps import method used at the time was numpy.genfromtxt(), that much is clear.

 

I have tried using numpy.fromfile, numpy.genfromtxt and others in the Filter block itself without success and have been looking for possible examples of file import use in the 3.8.2.0 installed /example folders and elsewhere.

The filter taps do however populate directly from a GRC variable python list as real(floats), [1,1, –1, 1,1 ....]

Firdes is operable and the python wrappers for filter design populate the taps in much the same way.

 

The coefficient values are externally generated complex floats, but can be easily converted into other numeric or delimited text formats, as BPSK coding is being used. This much has been tried.

 

On a completely unrelated matter, I hope, the Filter Design Tool is inoperative.

 

I apologise if this is covering old ground again.

Regards,

David GD4FMB

David:

When you say "without success", what is the nature of the problem?  Filter response doesn't look right, you're getting an exception, etc etc.

Your externally-generated complex-floats--how are they represented in the file?  Do you specify dtype correctly when you read the file in?