[Eeglablist] How to create channel location file for BCI IV Dataset 1?

[Dibyajyoti Guha]

Dear EEGLab Community,
I am Dibyajyoti Guha, Faculty at GITAM University, Hyderabad, India.
I am working on academic research of BCI using EEGLab.
I am using BCI IV Dataset 1 from
https://urldefense.com/v3/__https://www.bbci.de/competition/iv/*dataset1__;Iw!!Mih3wA!AhdS9dYy83c4Dpa8KYdtuWWfNwTZGrzcJQHPKkyiy9ItNzjq50XV_0orvOrDHf1DAm8le_ORYlcvXdmld8vgW-DZ$  100Hz data: [ Matlab files
zipped (209 MB) ]
It has 59 channels.

My objective:
I want to create the channel location .locs type of file before I run ICA.

I have created a Matlab structure (by copy pasting from the Matlab
variables) using the following:

chanlocs = struct('index', {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58}, 'xposition',
{-0.201090284647584 0.201090284647584 -0.485474892457663 -0.328947368421053
-0.165352309388968 0 0.165352309388968 0.328947368421053 0.485474892457663
-0.605915412132058 -0.399195787896560 -0.197659348450441 0
0.197659348450441 0.399195787896560 0.605915412132058 -0.748346834141953
-0.524729756596237 -0.309639112357972 -0.102263028316316 0.102263028316316
0.309639112357972 0.524729756596237 0.748346834141953 -0.877192982456140
-0.645690583415569 -0.421549001338212 -0.207737565050372 0
0.207737565050372 0.421549001338212 0.645690583415569 0.877192982456140
-0.748346834141953 -0.524729756596237 -0.309639112357972 -0.102263028316316
0.102263028316316 0.309639112357972 0.524729756596237 0.748346834141953
-0.605915412132058 -0.399195787896560 -0.197659348450441 0
0.197659348450441 0.399195787896560 0.605915412132058 -0.485474892457663
-0.328947368421053 -0.165352309388968 0 0.165352309388968 0.328947368421053
0.485474892457663 -0.103958649420094 0.103958649420094 -0.171131861417656
0.171131861417656}, 'y_positions', {0.686565177105246 0.686565177105246
0.525474237033963 0.465201829727992 0.432086407208813 0.421549001338212
0.432086407208813 0.465201829727992 0.525474237033963 0.271657042421725
0.233843478507591 0.213944937077633 0.207737565050372 0.213944937077633
0.233843478507591 0.271657042421725 0.151771690883298 0.125531031531108
0.110860959086494 0.104266479482922 0.104266479482922 0.110860959086494
0.125531031531108 0.151771690883298 0 0 0 0 0 0 0 0 0 -0.151771690883298
-0.125531031531108 -0.110860959086494 -0.104266479482922 -0.104266479482922
-0.110860959086494 -0.125531031531108 -0.151771690883298 -0.271657042421725
-0.233843478507591 -0.213944937077633 -0.207737565050372 -0.213944937077633
-0.233843478507591 -0.271657042421725 -0.525474237033963 -0.465201829727992
-0.432086407208813 -0.421549001338212 -0.432086407208813 -0.465201829727992
-0.525474237033963 -0.655838116128691 -0.655838116128691 -0.860337965265992
-0.860337965265992}, 'labels',
{'AF3','AF4','F5','F3','F1','Fz','F2','F4','F6','FC5','FC3','FC1','FCz','FC2','FC4','FC6','CFC7','CFC5','CFC3','CFC1','CFC2','CFC4','CFC6','CFC8','T7','C5','C3','C1','Cz','C2','C4','C6','T8','CCP7','CCP5','CCP3','CCP1','CCP2','CCP4','CCP6','CCP8','CP5','CP3','CP1','CPz','CP2','CP4','CP6','P5','P3','P1','Pz','P2','P4','P6','PO1','PO2','O1','O2'}
;
writetable(struct2table(chanlocs), 'BCI4_Data1_Channel_Location.txt');

After storing the MATLAB structure as .txt file, I have removed the comma,
and inserted a space between consecutive columns to create the location
file with name of "BCI_channel_location.loc", which looks like below
(first  4 lines are produced):

1 -0.201090284647584 0.686565177105246 AF3
2 0.201090284647584 0.686565177105246 AF4
3 -0.485474892457663 0.525474237033963 F5
4 -0.328947368421053 0.465201829727992 F3

After importing the 3D trial data alongwith  "BCI_channel_location.loc"  ,
I see that channels are located in a linear fashion (by clicking in
Plot-2D).

Please help me in creating the channel location file correctly.


-- 

With regards,
 Dr. Dibyajyoti Guha.
Github: https://urldefense.com/v3/__https://github.com/dguhanus__;!!Mih3wA!AhdS9dYy83c4Dpa8KYdtuWWfNwTZGrzcJQHPKkyiy9ItNzjq50XV_0orvOrDHf1DAm8le_ORYlcvXdmldw8YIS-c$ 
Linkedin: https://urldefense.com/v3/__https://sg.linkedin.com/in/dibyajyoti-guha-08117715__;!!Mih3wA!AhdS9dYy83c4Dpa8KYdtuWWfNwTZGrzcJQHPKkyiy9ItNzjq50XV_0orvOrDHf1DAm8le_ORYlcvXdmld2mLlPN2$ 
ORCID: https://urldefense.com/v3/__https://orcid.org/0000-0003-0735-3047__;!!Mih3wA!AhdS9dYy83c4Dpa8KYdtuWWfNwTZGrzcJQHPKkyiy9ItNzjq50XV_0orvOrDHf1DAm8le_ORYlcvXdmld14054Rn$