Error in grand-average mean

[Zrn1213]

I added two virtual channels (the averages of certain existing channels) to a series of .set files, which resulted in the corresponding .erp files. However, after averaging this series of .erp files, I noticed that the values of each channel were several tens of times larger than the actual values. Why is this happening? The values were normal after the first conversion step.
In fact, I want to compute the SEM for the two virtual channels (the averages of certain existing channels) ,how to get it?
I use EEGLAB v2021.0 ERPLAB v8.10

[davidg622]

Hello,

When you are creating the .erp files, are you only using the two virtual channels? It would help if you could email me a sample of your data so I can see what's going on. Please email me at [email protected]

Thanks,

David