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Offline Analysis -- Invalid trial change condition specified
Posted: 13 Aug 2008, 17:14
by lynn
Hi,
I get an error:"Invalid trial change condition specified" when I generate plots following the instructions of "Performing a Time-Domain Offline Analysis of EEG Data".
The value of Trial change Condition variables is set by default so I did not change it at first. After the error, I also input the value manually to make sure they are capitalized correctly, but still error.......
Does anyone have any idea about this error?
Thank you.
-- lynn
Posted: 14 Aug 2008, 08:34
by DSullivan
Which value are you using? I was using (states.Flashing == 1), which worked in older versions of the software, but in version 2.0 I was getting the same error as you until I learned that it should now be (states.StimulusBegin == 1)
Posted: 14 Aug 2008, 12:34
by josh
Hey all,
I apologize for the confusion here. When BCI2000 v2 was released the default state variable names were changed. So, where we had states.Flashing before, we have states.StimulusBegin now. Unfortunately, the sample files included with BCI2000 were v1.x files and, in many cases, had old file names. So, as was mentioned in the last post, you will probably be able to fix the problem simply by changing that variable name. Of course, the best way to figure out the what the problem is is by inspecting the state data. You can do this by opening up the BCI2000 Viewer (bci2000/tools/BCI2000Viewer/BCI2000Viewer.exe). Then, if you drag your data file into the application, you'll see a list of all the state variables used in the file. You'll also be able to see how they behave in conjunction with the signal. Very often, however, the name of the variable alone is enough to gain some understanding of its function. That all said, the newest release of BCI2000 OfflineAnalysis and the corresponding sample files should work together in harmony

. Please let me know if continue having problems.
Thanks,
Josh
Posted: 15 Aug 2008, 13:25
by lynn
DSullivan wrote:Which value are you using? I was using (states.Flashing == 1), which worked in older versions of the software, but in version 2.0 I was getting the same error as you until I learned that it should now be (states.StimulusBegin == 1)
I used StimulusBegin before. The error is gone after I change it to Flashing.
Thank you ^_^
Posted: 15 Aug 2008, 13:25
by lynn
Oh...I see...
Thanks~~
josh wrote:Hey all,
I apologize for the confusion here. When BCI2000 v2 was released the default state variable names were changed. So, where we had states.Flashing before, we have states.StimulusBegin now. Unfortunately, the sample files included with BCI2000 were v1.x files and, in many cases, had old file names. So, as was mentioned in the last post, you will probably be able to fix the problem simply by changing that variable name. Of course, the best way to figure out the what the problem is is by inspecting the state data. You can do this by opening up the BCI2000 Viewer (bci2000/tools/BCI2000Viewer/BCI2000Viewer.exe). Then, if you drag your data file into the application, you'll see a list of all the state variables used in the file. You'll also be able to see how they behave in conjunction with the signal. Very often, however, the name of the variable alone is enough to gain some understanding of its function. That all said, the newest release of BCI2000 OfflineAnalysis and the corresponding sample files should work together in harmony

. Please let me know if continue having problems.
Thanks,
Josh