[Eeglablist] writing cnt files

[arno delorme]

Nasser,

the read_eep_cnt() is a function to read CNT files from the ANT  
company not from Neuroscan. loadcnt is the correct function. This  
function is pretty stable, so if you have problem, it is likely that  
it comes from the writecnt function which is relatively unstable (and  
not part of EEGLAB per say).

An alternative method would be to write to EDF format using BIOSIG  
(swrite function) then open the EDF file under Neuroscan - I think  
Neuroscan can open EDF file but I am not sure as I have not used this  
software in a long time (of course you will loose in data resolution  
since EDF is 16-bit and CNT is currently 32). That's probably the best  
option.

Arno

On 12 janv. 09, at 11:17, Nasser Mourad wrote:

> Dear EEGlab group
>
> I am trying to write a neuroscan continuous signal file  
> (file_name.cnt)
> using the function “writecnt.m”, and I followed the following steps:
>
> 1- cnt = loadcnt(file_name, 'scale', 'off', 'sample1', 0,  
> 'blockread', 1,'ldnsamples', 1000);
> 2. cnt.endtag = cnt.tag;
> 3. writecnt(out_file_name,  cnt, 'scale', 'off', 'sample1', 0,  
> 'ldnsamples', 1000);
>
> To this stage; it seems that every thing is working fine, but after  
> that when I tried to read the data using eeglab or the command line  
> function
> [eeg] = read_eep_cnt(out_file_name,1,1000);
> I get the following error message ”??? Error reading header from  
> file”.
> To me, it seems that the main problem comes from the matlab script  
> “loadcnt.m”, that I used first to read the data, because by checking  
> the size of the data set (size(cnt.data)) I found that the number of  
> channels is 4201 instead of 129!!!!
>
> Any idea what I have to do to fix that error?
> Thanks in advance,
>
> Nasser
>
>
>
>
> <ATT00001.txt>

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