[Eeglablist] Re: importing edf file

[Alois Schloegl]

eeglablist-request at sccn.ucsd.edu wrote:

>Date: Wed, 25 Jan 2006 12:07:50 +0100
>From: "stefano ferraina" <stefano.ferraina at uniroma1.it>
>Subject: [Eeglablist] importing edf file
>To: <eeglablist at sccn.ucsd.edu>
>Message-ID: <004101c6219f$95f27790$2e286497 at sfnew>
>Content-Type: text/plain; charset="iso-8859-1"
>
>I do have a problem importing big edf files in EEGlab (using the BIOSEMI tool).
>For example, the last file is 120 Mb and with 105 channels recorded.
>No problem with a smaller file.
>
>It looks like that there is a problem with memory. I used both the clean and the pack from matlab to increase the amount of available memory as well as I increased up to the maximum (4 GB) the virtual memory from the Windows control panel.
>  
>
I guess you are using windows, increasing the virtual memory does not 
help; you need real RAM. 120Mb EDF data will result 480 MByte Matlab 
data; besides the operating system needs also memory.

>The error message 'out of memory' is still there:
>
>as well as the warning:
>
>Warning SOPEN: OVERFLOWDETECTION not supported because of missing THRESHOLD.
>
>??? Reference to a cleared variable EEGTMP.
>
>??? Error while evaluating uimenu Callback.
>  
>

>Any suggestion?
>  
>

You can buy more RAM, switch from Windows to Linux (Linux needs less 
memory) or

you can load parts of the data in this way:

CHAN = 1:4;       % select channels
[data,HDR]=sload(filename,  CHAN);       % select only channels listed 
in CHAN

or

HDR=sopen(filename,'r',CHAN);
[data,HDR]  =  sread(HDR,LEN,START);     % read data block of length 
"LEN", starting at "START".
HDR=sclose(HDR);



Alois