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About Neuroscan block size

Posted: 26 Apr 2012, 22:03
by RobinWang
Hi, I used NuAmps and neurogetparams.exe got the test.prm file. Now I have some question.
I set the A/D Rate=1000Hz, then the block size=40. I load the test.prm and found the value of AlignChannels was -1, SourceChTimeOffset was 1.These parameters caused some errors.
But when A/D Rate was set to 250Hz, the parameters were changed. blocksize =32, AlignChannels was 0, SourceChTimeOffset was empty.
Whether a relationship with A/D Rate or block size?
Which A/D Rate is better?

Re: About Neuroscan block size

Posted: 27 Apr 2012, 05:46
by mellinger
I load the test.prm and found the value of AlignChannels was -1, SourceChTimeOffset was 1.These parameters caused some errors.
When you have AlignChannels enabled (i.e., not 0), then SourceChTimeOffset must be either empty, or set to values between 0 and 1. The number of entries in SourceChTimeOffset must match the number of channels.
For more information about channel alignment, see
http://www.bci2000.org/wiki/index.php/U ... mentFilter

I fixed the neurogetparams program, so it returns correct parameters now.