[Eeglablist] Merging two datasets with unequal numbers of events

[Tarik S Bel-Bahar]

Hi Elizabeth, some notes below that might help. this shouldn't be a
problem, and if it's repeatable please consider reporting in eeglab
bugzilla.

The error of course suggests that one of your files does not have urevents,
which I think are/should-be generated when a file is first loaded and saved
in eeglab.
I recommend making sure that you've done the following, which should lead
you past this error.

importing, epoching, and saving the two files the same way as much as
possible, so there is nothing different between them except the number and
type of epoch.
both files should have a "number of epochs" in the eeglab gui
both files "should" have an urevents field (unless there were no events in
the file used originally?-not sure about this, see online wiki on events
and urevents)
both files should have an 3-dimensional EEG.data structure
both files should have the same-length epochs
both files should already be healthily saved and re-openable in eeglab as
.set files, prior to attempt at merging
both files are actively in memory as Datasets 1 and 2 (or however many
datasets you're merfing.

Other than this, first two a successful mergeset and review the command
that was run using eegh. Try it on two files that are copy of each of other.
You may also attempt to comment out line 275 or near there in the code to
attempt to bypass the error, but this is NOT recommended unless you're
matlab saavy and can read the full function code.



On Wed, Oct 26, 2016 at 2:44 PM, Elizabeth Spencer Norton <
enorton at northwestern.edu> wrote:

> Hello,
>
> I'm trying to merge (concatenate) two datasets with different numbers of
> events. We run an oddball paradigm with randomly selected number of
> standards between deviants, and this is done in two runs that have
> different stimuli. I'm trying to concatenate the two runs using the GUI
> which calls pop_mergeset, but getting the error popup "EEGLAB error in
> function pop_mergeset() at line 275: Reference to non-existent field
> 'urevent'."
>
>
> Looking at the pop_mergeset script, it looks like it wants to merge the
> files and insert a boundary event halfway through (lines 224-228), which
> may be the problem with using two files of unequal length. (Using EEGLab
> version 13.6.5.)
>
>
> I'd prefer not to just lop off events from the longer dataset to make the
> sizes match. If anyone has ideas for other solutions, I would appreciate it!
>
> Best,
>
> Elizabeth Norton
>
> Northwestern University
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to eeglablist-unsubscribe at sccn.
> ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20161027/900904e9/attachment.html>