# Fw: Re: Error in executing filtering example **URL:** \ **Category:** GNU Radio\ **Created:** [February 1, 2013, 4:00pm UTC](https://www.ruby-forum.com/t/fw-re-error-in-executing-filtering-example/229411 "2013-02-01T16:00:30Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Ghulam\_Rasool\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/bc8723/32.png) [@Ghulam\_Rasool\_B](https://www.ruby-forum.com/u/Ghulam_Rasool_B)\ **Post date:** [February 1, 2013, 4:00pm UTC](https://www.ruby-forum.com/t/fw-re-error-in-executing-filtering-example/229411/1 "2013-02-01T16:00:30Z")
— On Fri, 2/1/13, Ghulam Rasool B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: From: Ghulam Rasool B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Error in executing filtering example To: “Tom R.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Date: Friday, February 1, 2013, 8:28 PM Thanks for reply. Actually from the presentation I could get all values but for variable block with ID as taps , i was not sure what value I should choose as it was not clear from the presentation i downloaded. I guess if proper value is given to that block, the flow graph will run. — On Fri, 2/1/13, Tom R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: From: Tom R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Error in executing filtering example To: “Ghulam Rasool B.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Cc: “Gnu Radio” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Date: Friday, February 1, 2013, 8:04 PM On Fri, Feb 1, 2013 at 12:00 AM, Ghulam Rasool B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Hi all, I was simulating filtering.grc example fromDigital Modulation Primer using GNU Radio by Tom R…However during execution it gives following error. Can anybody help it out. Executing: “/home/ehsan/mygn/filtering.py” Traceback (most recent call last): File “/home/ehsan/mygn/filtering.py”, line 119, in tb = filtering() File “/home/ehsan/mygn/filtering.py”, line 83, in **init** self.fft\_filter\_xxx\_0 = filter.fft\_filter\_ccc(1, (), 1) File “/usr/local/lib/python2.7/site-packages/gnuradio/filter/filter\_swig.py”, line 677, in make return \_filter\_swig.fft\_filter\_ccc\_make(\*args, \*\*kwargs) RuntimeError: fft\_impl\_fftw: invalid fft\_size > > > Done With RegardsG R Begh Can you tell us what you were doing when you go this error? Was it running at all? Tom ---
**Author:** ![Ghulam\_Rasool\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/bc8723/32.png) [@Ghulam\_Rasool\_B](https://www.ruby-forum.com/u/Ghulam_Rasool_B)\ **Post date:** [February 1, 2013, 6:43pm UTC](https://www.ruby-forum.com/t/fw-re-error-in-executing-filtering-example/229411/2 "2013-02-01T18:43:05Z")
On Fri, Feb 1, 2013 at 9:59 AM, Ghulam Rasool B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)wrote: > Thanks for reply. > Actually from the presentation I could get all values but for _variable > block_ with ID as taps , i was not sure what value I should choose as it > was not clear from the presentation i downloaded. I guess if proper value > is given to that block, the flow graph will run. The ‘taps’ variable are the filter taps that go into the FFT Filter block. As you change these taps, you change the response of the filter. It is already filled in as " firdes.low\_pass\_2(1, samp\_rate, bw, bw/10.0, 80)" Where ‘samp\_rate’ is static variable set to 100 ksps and the ‘bw’ is a dynamic variable that can be changed at runtime by the Qt slider. Tom ---
**Author:** ![Ghulam\_Rasool\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/bc8723/32.png) [@Ghulam\_Rasool\_B](https://www.ruby-forum.com/u/Ghulam_Rasool_B)\ **Post date:** [February 1, 2013, 8:42pm UTC](https://www.ruby-forum.com/t/fw-re-error-in-executing-filtering-example/229411/3 "2013-02-01T20:42:17Z")
Thanks it worked. — On Fri, 2/1/13, Tom R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: From: Tom R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Fw: Re: Error in executing filtering example To: “Ghulam Rasool B.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Cc: “Gnu Radio” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Date: Friday, February 1, 2013, 8:32 PM On Fri, Feb 1, 2013 at 9:59 AM, Ghulam Rasool B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: — On Fri, 2/1/13, Ghulam Rasool B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: From: Ghulam Rasool B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Error in executing filtering example To: “Tom R.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Date: Friday, February 1, 2013, 8:28 PM Thanks for reply. Actually from the presentation I could get all values but for variable block with ID as taps , i was not sure what value I should choose as it was not clear from the presentation i downloaded. I guess if proper value is given to that block, the flow graph will run. The ‘taps’ variable are the filter taps that go into the FFT Filter block. As you change these taps, you change the response of the filter. It is already filled in as “firdes.low\_pass\_2(1, samp\_rate, bw, bw/10.0, 80)” Where ‘samp\_rate’ is static variable set to 100 ksps and the ‘bw’ is a dynamic variable that can be changed at runtime by the Qt slider. Tom — On Fri, 2/1/13, Tom R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: From: Tom R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Error in executing filtering example To: “Ghulam Rasool B.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Cc: “Gnu Radio” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Date: Friday, February 1, 2013, 8:04 PM On Fri, Feb 1, 2013 at 12:00 AM, Ghulam Rasool B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Hi all, I was simulating filtering.grc example fromDigital Modulation Primer using GNU Radio by Tom R..However during execution it gives following error. Can anybody help it out. Executing: “/home/ehsan/mygn/filtering.py” Traceback (most recent call last): File “/home/ehsan/mygn/filtering.py”, line 119, in tb = filtering() File “/home/ehsan/mygn/filtering.py”, line 83, in **init** self.fft\_filter\_xxx\_0 = filter.fft\_filter\_ccc(1, (), 1) File “/usr/local/lib/python2.7/site-packages/gnuradio/filter/filter\_swig.py”, line 677, in make return \_filter\_swig.fft\_filter\_ccc\_make(\*args, \*\*kwargs) RuntimeError: fft\_impl\_fftw: invalid fft\_size > > > Done With RegardsG R Begh Can you tell us what you were doing when you go this error? Was it running at all? Tom * * * Discuss-gnuradio mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > **[Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)**