[Eeglablist] Event type changes when exporting from EGI .RAW to BDF

Ana Laura Diez Martini diezmartini at gmail.com
Sun May 18 15:28:23 PDT 2014


Hello!

I'm new both to EEGlab and Mathlab and I haven't been able to solve a problem.

I'm using an EGI system in my new experiment and I used BIOSEMI for
previous ones. My current output file is in .RAW format and I want to
use my old scripts written for BDF files (I used Fieldtrip) to analyse
this new data. The problem is, when I try to export it to BDF I get
these warnings:

Warning SOPEN (EDF-Write): relative scaling error is 2.636733e-05 (due
to roundoff in PhysMax/Min)
Warning SWRITE: 174 NaNs added to complete data block.

Then the name of the triggers (the event type) changes completely.

I don't know if this has anything to do with it but the trigger codes
in my program (using Presentation) had this format: 11, 12, 13, 14,
15,21, 22...etc. However, Netstation codes them differently. For
example trigger "11" would come out as 3 different events: 1,2,8, or
"12" would be 4 and 8. So I have to use a piece of code to convert
them to one event summing up the others with the same latency. I also
tried exporting to BDF without this conversion and it won't work
either. In any case, I need to export it to have the new event types
saved.

Just to clarify, again what I need is to get a BDF file from a .RAW
file with the same events so I can use my old scripts. I'm sorry if
I'm missing a lot from my lack of knowledge, I have been reading but I
couldn't find anything to solve this.

THANK YOU!!

PS: Please let me know if I can upload any of my files to help
understand my problem


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