Re: Rational resampler does not change behaviour when changing the decimaton rate

[Jeff Long]

Any field that is underlined may be changed at run time. Fields that are not underlined can not be changed at run time, and will remain at the value they had when the flowgraph started.

Also, keep in mind that taps typically depend on the resampling ratio. If no taps are specified for the rational resampler, it generates its own based on the other 3 parameters, but if the user provides taps, changing the ratio at run time may not give the expected result.

On Sun, Nov 28, 2021 at 3:55 AM Fernando Peral <fernando@samara.com.es> wrote:

I gues you said   that taps being underlined  means that decimation can't be changed at run time.

I have tested the same diagram with decimating FIR filter, rational resampler and fractional resampler, with the third one it works like I wanted, it change in runtime, with the other two (both of them have a underlined taps) it don't.

On 28/11/21 2:58, Jeff Long wrote:

You are correct. Note that in the params dialog, only "taps" is underlined. This means that decimation can be changed at runtime.

I'm not sure whether there is an easy change that can be made to support what you want. If you feel this is important, please add a feature request as an issue (https://github.com/gnuradio/gnuradio/issues).

On Sat, Nov 27, 2021 at 7:53 PM Fernando Peral <fernando@samara.com.es> wrote:

I'm using the following  diagram to test it, where

the first freq sink (x1) has bandwidth fixed to samp_rate/1  and its rational resampler have decimation fixed to 1

the second freq sink (x2) has bandwidth fixed to samp_rate/2  and its rational resampler have decimation fixed to 2

the third freq sink (x5) has bandwidth fixed to samp_rate/5  and its rational resampler have decimation fixed to 5

the fourth freq sink (variable) has bandwidth fixed to samp_rate/decimation  and its rational resampler have decimation fixed to decimation

I run the diagram, decimation default value is 1 and all seems to work

Then I change  decimation in the GUI Range  and the variable block don't work

Then I stop the diagram, change the default value of the GUI range to  2

I run it again .... it works

Then I change the value of decimation in the GUI range ....  and it does not work

The x axis change but the "image" don't ...   what am I doing bad?