[Eeglablist] 1. Re: Channel Location File (Stephen Politzer-Ahles)

[Khaled Al-Kamha]

Dear Tarik,

I think what happened is there is two versions of my question, i'll try to
avoid that.

The eeglab reads the locations if the labels known via "Look up locs"
button, and the dataset that i'm working in offer that
http://www.physionet.org/pn4/eegmmidb/,
i just have to make sure that the labels named correctly, for example "C3"
instead of "C3.." and the "Look up locs" works perfectly.

Thank you for your explanations, i don't have time now for understanding
EGI location files, but i will find it and i'll be sure to post the file to
the eeglab locations page soon.

I'm not using any egi system and 'm not an expert in this field.

Best,
Khaled


On Thu, Dec 27, 2012 at 10:17 PM, Tarik S Bel-Bahar <tarikbelbahar at gmail.com
> wrote:

> Hi Khaled,
>
> just a few quick thoughts that might help you...let us know of your
> success. When you are done
> please be sure to post your file to the eeglab locations page.
>
> I think when it says .txt file, it means that EEGLAB can accept location
> files that are in a text format.
> That being said, I am sure the info within the text file has to be
> formatted correctly. You can check
> yourself by looking at the content of example channel location files.
> Eeglab generally can recognize and import most of these file types.
>
> The EGI document table basically lists labels (such as the 10-10 labels)
> in the first column.
> For example, on page 7, using a 128 channel Hydrocel EGI montage, the
> closest to C3 is channel 36.
> If you read the explanation, the arclength should be total estimated error
> in distance between the
> actual electrode and the ideal 10-10 label in question.
>
> Just be careful because there are old and new(hydrocel) EGi location files.
> In the past, what I did was within eeglab, I modified the labels for the
> channels with the correct 10-10 labels
> for an egi system. If you are indeed using a 64-channel net, then you need
> to find the correct files
> and 10-10 or 10-20 matches for that montage. If using EGI system, you can
> contact egi support
> if you don't find it by searching further on their ftp site. You should
> have already found this
> tech note there:
> http://ueleeglabwiki.pbworks.com/f/200_ElectrodePositions.pdf
>
> some other points: it's not clear if you are using an egi system, and
> whether you actually have
> a general locations file for the 64 net that you are using.
>
> Good luck with your process!
>
>
> On Thu, Dec 20, 2012 at 1:56 PM, Khaled Al-Kamha <khaled.alkamha at gmail.com
> > wrote:
>
>> Hi Steve,
>>
>> I'm working on EGGLAB, and as i see here
>> ftp://sccn.ucsd.edu/pub/locfiles/ EEGLAB channel location formats are:
>>
>> ".loc" for polar coordinates
>> ".xyz" for 3-d carthesian coordinates
>> ".sph" for 3-d spherical coordinates
>> ".txt" for all coordinates formats
>>
>> It seems i need the ".txt" file for further steps, but i didn't find it
>> for my 10/10 standard and 64 channels.
>> actually, i have kind of poor experience in this field and critical time
>> for my graduation project, plus i didn't fully understand what the table
>> means ftp://ftp.egi.com/pub/documentation/technotes/HydroCelGSN_10-20.pdf
>> Any simple explanations, i appreciate it
>>
>> Thanks in advance
>>
>> On Wed, Dec 19, 2012 at 4:01 AM, <eeglablist-request at sccn.ucsd.edu>wrote:
>>
>>>  1. Re: Channel Location File (Stephen Politzer-Ahles)
>>
>>
>>
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>
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