matlab to csv file

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student
Posts: 16
Joined: Mon Feb 02, 2015 2:46 pm

matlab to csv file

Post by student »

Hi everyone,

I am a newbie here.

Currently I am working on cognitive bci, I designed my own scenario for offline experiment before going into online experiment.
I try to use the offline data which was coded in matlab. I imported the matlab code to openvibe using csv formate.

There is some problem with csv reader, since it can send the data from temperal filter block but it can not send the signal after epoching. I am unable to find the problem with it. I would be really happy to get some help or guidence from you guys.

Thanking you,
GR

jtlindgren
Posts: 775
Joined: Tue Dec 04, 2012 3:53 pm
Location: INRIA Rennes, FRANCE

Re: matlab to csv file

Post by jtlindgren »

Hi Student, welcome abroad!

Could you explain in a bit more detail how the boxes are connected, what are the inputs and what outputs you expect?


Cheers,
Jussi

student
Posts: 16
Joined: Mon Feb 02, 2015 2:46 pm

Re: matlab to csv file

Post by student »

hi jussi,

Thank you for your response.

sure, I wanted to try the offline data recording of a task. I converted this matlab data into csv file.

1) I added the csv reader block and then a temporal filter (Butterworth Bandpass) and added a signal display block to check the output signal after the filter.
2) with the temporal filter block I connected the time based epoching block and then another signal display block to check the output signal after the epoching.

The problem is i can see the filtered signal but i can't see the signal after the epoching.
I could not find the reason. Thank you.

Ps: I have also attached the image of the scenario for your reference

Cheers,
GR
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jtlindgren
Posts: 775
Joined: Tue Dec 04, 2012 3:53 pm
Location: INRIA Rennes, FRANCE

Re: matlab to csv file

Post by jtlindgren »

For one thing, your signal display box says 'update' suggesting that you need to drag a new box to the canvas and set its parameters again. Otherwise its operation may be incorrect.

In addition, I'd suggest trying with default values of the time based epoching box and see what happens. If the epoch size is very large, it can take a long time before
anything is drawn, as the drawing is only done after each epoch has been fully received. Also, if epochs overlap in time, whats shown can look 'funny'.


Happy hacking,
Jussi

student
Posts: 16
Joined: Mon Feb 02, 2015 2:46 pm

Re: matlab to csv file

Post by student »

I tried all the possible option by changing the blocks and epoching of 1 sec duration with 0.5 sec interval but its not working.
I replaced csv block with gdf block then its working. The problem is with the csv block, I don't know why :(

Thanks & regards,
GR

jtlindgren
Posts: 775
Joined: Tue Dec 04, 2012 3:53 pm
Location: INRIA Rennes, FRANCE

Re: matlab to csv file

Post by jtlindgren »

Which OpenViBE version? Can you give me a link to your .csv file? (dropbox, or such).


Best,
Jussi

student
Posts: 16
Joined: Mon Feb 02, 2015 2:46 pm

Re: matlab to csv file

Post by student »

sorry, I just notices the reply. I am using the updated version of Openvibe. i need email to share the dropbox.

Mean while I have another one problem. I try to record the data in the real time. I added "Generic Stream Writer " to record the real time data but i could not able to save this file.
It shows only open option not the option of save. I will be happy to get some help from you on this. Thanking you :)

Thank you,
GR

jtlindgren
Posts: 775
Joined: Tue Dec 04, 2012 3:53 pm
Location: INRIA Rennes, FRANCE

Re: matlab to csv file

Post by jtlindgren »

In the generic stream writer configure window, you just configure the box parameters. The actual saving will be done during playback. The box will write to the file you have selected as long as the 'play' runs.


Cheers,
Jussi

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