[Eeglablist] BDF data range

[arno]

Dear Quentin,

in the latest version of EEGLAB (5.03), you should use pop_biosig() 
instead of pop_readbdf() (this is mentioned in the function header). It 
might not respond to your question below though.

> - After opening  a bdf file recorded with Biosemi in EEGlab
> EEG = pop_readbdf(filename);
> what is the range of the data in EEG.data ? Are they between physical min
> and physical max or between digital min and digital max ?
>
> - While checking the BIOSIG files, I realised than sometimes the bdf data
> are multiplied by the gain :
> (physmax -physmin) ./ (digmax - digmin)
> and sometimes they are multiplied by the gain and then the following
> factor is added:
> physmin - digmin*gain
>
> This depends on a flag but I did not go far enough to understand the flag.
> The first solution was also proposed recently on this list.
> Why such a difference ?
>   

I do not know but maybe Alois could answer this question?

Thanks a lot,

Arno