Search found 23 matches
- 17 Nov 2011, 12:33
- Forum: BCI Systems - Signal Processing
- Topic: ARFilter Spectral Estimation
- Replies: 14
- Views: 12560
Re: ARFilter Spectral Estimation
thank you Alessandro!! the problem is that i control the value during the online operation and they differ a lot from the values obteined during the offline analysis. I think that the only parameters that could be different is "NumericWindow" because i don't understand where is setted in ...
- 17 Nov 2011, 10:52
- Forum: BCI Systems - Signal Processing
- Topic: ARFilter Spectral Estimation
- Replies: 14
- Views: 12560
Re: ARFilter Spectral Estimation
Hi, i have the opposite problem. during online analysis, i want to obtain with the ARFilter the same spectra as that in the offline analysis. It's too important for me because i want to determine a threshold value looking the spectra plot and the r^2 plot obteined in the offline analysis and use it...
- 17 Jun 2011, 14:31
- Forum: BCI Systems - Signal Processing
- Topic: ARFilter Spectral Estimation
- Replies: 14
- Views: 12560
Re: ARFilter Spectral Estimation
Thanks, I appreciated it. I'm sorry but still I can't get it. Let me try with an example. I have attached a snapshot of AR filter parameters' configuration. Let's assume that I want to use the same configuration in Matlab when calling the mem function. Would my parameters be: sampfreq = 512; ModelOr...
- 14 Jun 2011, 12:29
- Forum: BCI Systems - Signal Processing
- Topic: ARFilter Spectral Estimation
- Replies: 14
- Views: 12560
Re:
Hi, for offline simulations, BCI2000 comes with two tools which might be interesting to you: A) Command line processing ( http://www.bci2000.org/wiki/index.php/User_Reference:Command_Line_Processing ) allows you to apply BCI2000 filters to offline data, interrupt the processing at any point, and st...
- 14 Jun 2011, 11:59
- Forum: BCI Systems - Signal Processing
- Topic: Multiple Channels (EEG & Galvanic Skin Response)
- Replies: 2
- Views: 4409
Re: Multiple Channels (EEG & Galvanic Skin Response)
I'm definitely not an expert, but I think you should be able to do it. You just need to set the Transmission Filter in order to transmit only the channels that you are interested in processing online. In the SOURCE menu, scroll down to the bottom and you will find TransmitChList. The GSR channels wi...
- 14 Jun 2011, 11:01
- Forum: BCI Systems - Signal Processing
- Topic: Trouble using mem() function in MATLAB
- Replies: 2
- Views: 4018
Re: Trouble using mem() function in MATLAB
Hey Gerv,
as always thank you so much. I tested and you were right, LastBinCenter and BinWidth must be specified in Hz and not as normalized frequency.
Thanks,
Alessandro
as always thank you so much. I tested and you were right, LastBinCenter and BinWidth must be specified in Hz and not as normalized frequency.
Thanks,
Alessandro
- 13 Jun 2011, 16:55
- Forum: BCI Systems - Signal Processing
- Topic: Trouble using mem() function in MATLAB
- Replies: 2
- Views: 4018
Trouble using mem() function in MATLAB
Hi, I'm trying to use the mem() function in MATLAB with EEG signals imported using load_bcidat('..','-calibrated'), but the plots I get are very weird, the spectral power decreases exponentially. So in order to test the MEM function I'm trying to use some sinusoidal inputs plus white noise (because ...
- 08 Jun 2011, 12:11
- Forum: BCI Systems - Signal Processing
- Topic: Command line processing and matlab
- Replies: 6
- Views: 6522
Re: Command line processing and matlab
Hi Alessandro, I cannot find a significant difference between files loaded by load_bcidat vs load_bcimat. This is what I did: First I executed on the command line: bci_dat2stream < yuriS001R07.dat | TransmissionFilter | bci_stream2mat > yuriS001R07.mat Then, in Matlab: >> m = load_bcimat( 'yuriS001...
- 08 Jun 2011, 10:45
- Forum: BCI Systems - Signal Processing
- Topic: Command line processing and matlab
- Replies: 6
- Views: 6522
Re: Command line processing and matlab
mellinger wrote:Dear Alessandro,
could you send me the data file in question, so I can try myself?
Best regards,
Juergen
Sure.
I have attached the acquisition run I have used.
Thank you so much for your help.
Alessandro
- 08 Jun 2011, 09:59
- Forum: BCI Systems - Signal Processing
- Topic: Command line processing and matlab
- Replies: 6
- Views: 6522
Re: Command line processing and matlab
Dear Juergen, thank you so much for your reply. I imported in Matlab the signals as calibrated, in both cases. Default for load_bcimat() and '-calibrated' mode for load_bcidat(). Moreover I have made sure that SourceChOffset is set to zero and SourceChGain (that gives calibrated units) is non-zero. ...
- 07 Jun 2011, 11:06
- Forum: BCI Systems - Signal Processing
- Topic: Command line processing and matlab
- Replies: 6
- Views: 6522
Command line processing and matlab
Hey everyone, I have a new issue. I'm working offline using the command line processing and importing then the results in matlab. But when I compare my data imported in matlab using the load_bcidat() function to the data generated by the command line " bci_dat2stream < mydata.dat | Transmission...
- 31 May 2011, 09:51
- Forum: BCI Systems - Signal Processing
- Topic: Help with data analysis
- Replies: 2
- Views: 3903
Re: Help with data analysis
Hello Dr. Schalk, Thank you so much for your reply. Hi, It seems as if the data are actually quite reasonable. R^2 of 0.2 with peaks at C3 and C4. I would do topographies in addition to the spectra, but you should see nice typical peaks over motor cortex. There is considerable inter-subject variatio...
- 27 May 2011, 13:00
- Forum: BCI Systems - Signal Processing
- Topic: Help with data analysis
- Replies: 2
- Views: 3903
Help with data analysis
Hi everybody. I have a question... I already know that is almost impossible for you to give me accurate answers, considering you don't know much on my data acquisition system... anyway, I have attached the results of the offline analysis of recently acquired data. It was a long training session with...
- 21 Mar 2011, 12:02
- Forum: BCI Systems - Brain Signals
- Topic: What's the best reference location to use?
- Replies: 1
- Views: 6488
What's the best reference location to use?
Hello,
I was wondering what the best location for the reference electrode is. I found some works where the authors used mastoids... what about earlobes? Can you please suggest some papers to support an eventual choice.
Thanks
Alessandro
I was wondering what the best location for the reference electrode is. I found some works where the authors used mastoids... what about earlobes? Can you please suggest some papers to support an eventual choice.
Thanks
Alessandro
- 23 Aug 2010, 16:28
- Forum: Software Development
- Topic: NIDAQ_mx source module development
- Replies: 2
- Views: 3273
Problem Solved
Hi, after some time spent debugging the code I realized that all my problems were related to data type conversion issues. Specifically, my A/D board digital output is a 16 bit unsigned integer and so all the acquisition part of the code must manage my data as unsigned integer. Then I converted this ...