bci2000.org BBS

Hello,

I'm working on setting up a P300 speller and I have run in to problems with loading a 128-electrode montage file in elocHelper. It says the .loc file I try to load is not a valid file, and so does OfflineAnalysis. The .loc file was converted from an .sfp-file. I tried making the file similar to a working sample .loc file, but this didn't work either (see examples below). Does anyone know how a .loc file should be organised for elocHelper and OfflineAnalysis to accept it?

.loc converted from .sfp:
1 46.352 0.59923 E1
2 38.265 0.48855 E2
3 26.847 0.39042 E3
...

working sample .loc file:
1 -68 0.3 Fc5.
2 -60 0.219 Fc3.
3 -42 0.14 Fc1.
...

changed .loc file:
1 46 0.599 E1..
2 38 0.489 E2..
3 27 0.390 E3..
...

Many thanks in advance!

Regards,

Thijs

P.S.: I tried to upload the files, but it won't let me.

Thijs,

make sure that line endings are in the correct format for your platform (CRLF on Windows).
Also, when the "acquisition type" is set to "eeg", the radius (third entry in the line) may not exceed the head radius specified in the tool's settings. Try "ecog" to disable this test.

HTH,
Juergen

Hello,

Using the ecog setting, I was able to get waveforms, thanks! I was not able to get scalp topographies, though, because "X and Y must be the same length as Z or the lengths of X and Y must match the size of Z". I guess this is because there are no Z coordinates in the .loc files. I tried adding 0's for Z data behind the X and Y but that didn't work.

cheers,

Thijs

Thijs,

the .loc files contain electrode coordinates in polar form (theta and r) rather than cartesian (x and y). Also, there is no z coordinate required.

Could you post your .loc file together with one of your data files? This would help me in debugging the Offline Analysis tool.

Cheers,
Juergen

Hi,

Sorry for the delay. I don't suppose uploading 40 MB to the forum is possible? I haven't been able to make BCI2000 only save the electrodes it uses for classification (is that even possible?), so the file contains the data for all 128 electrodes. Perhaps I could upload it to some ftp server?

Here is the contents of the .loc file:

1 46.352 0.59923 E1
2 38.265 0.48855 E2
3 26.847 0.39042 E3
4 21.874 0.31698 E4
5 14.582 0.22654 E5
6 0 0.14307 E6
7 -38.134 0.073411 E7
8 27.826 0.54733 E8
9 16.876 0.46286 Fp2
10 11.873 0.39053 E10
11 0 0.32024 E11
12 -14.582 0.22654 E12
13 -36.815 0.15618 E13
14 7.6337 0.53142 E14
15 0 0.45363 E15
16 0 0.39507 E16
17 0 0.57454 E17
18 -11.873 0.39053 E18
19 -21.874 0.31698 E19
20 -36.759 0.26161 E20
21 -7.6337 0.53142 E21
22 -16.876 0.46286 Fp1
23 -26.847 0.39042 E23
24 -36.524 0.33208 F3
25 -27.826 0.54733 E25
26 -38.265 0.48855 E26
27 -46.179 0.38996 E27
28 -53.144 0.31263 E28
29 -60.468 0.22774 E29
30 -75.432 0.14773 E30
31 -109.29 0.075536 E31
32 -46.352 0.59923 E32
33 -57.179 0.51491 E33
34 -66.491 0.39953 E34
35 -76.923 0.30135 E35
36 -87.023 0.226 C3
37 -111.23 0.15767 E37
38 -61.131 0.63414 E38
39 -83.259 0.53862 E39
40 -89.751 0.41016 E40
41 -96.616 0.31392 E41
42 -111.44 0.26014 E42
43 -69.655 0.70597 E43
44 -79.414 0.65035 E44
45 -104.33 0.5265 T3
46 -107.45 0.40397 E46
47 -114.09 0.33601 E47
48 -69.431 0.78544 E48
49 -86.215 0.74376 E49
50 -120.68 0.50937 E50
51 -125.44 0.39521 E51
52 -127.63 0.31143 P3
53 -133.91 0.22119 E53
54 -146.38 0.14754 E54
55 180 0.075944 E55
56 -111.71 0.72392 E56
57 -119.61 0.6198 E57
58 -133.64 0.49802 T5
59 -141.05 0.38986 E59
60 -145.82 0.29881 E60
61 -156.84 0.22326 E61
62 180 0.25512 Pz
63 -128.89 0.71847 E63
64 -137.37 0.61067 E64
65 -147.46 0.4952 E65
66 -154.79 0.38736 E66
67 -165.92 0.30797 E67
68 -149.4 0.69596 E68
69 -155.1 0.60324 E69
70 -162.35 0.49157 O1
71 -170.55 0.38353 E71
72 180 0.32829 E72
73 -165.57 0.68648 E73
74 -172.42 0.5953 E74
75 180 0.48275 Oz
76 170.55 0.38353 E76
77 165.92 0.30797 E77
78 156.84 0.22326 E78
79 146.38 0.14754 E79
80 109.29 0.075536 E80
81 180 0.67878 E81
82 172.42 0.5953 E82
83 162.35 0.49157 O2
84 154.79 0.38736 E84
85 145.82 0.29881 E85
86 133.91 0.22119 E86
87 111.23 0.15767 E87
88 165.57 0.68648 E88
89 155.1 0.60324 E89
90 147.46 0.4952 E90
91 141.05 0.38986 E91
92 127.63 0.31143 P4
93 111.44 0.26014 E93
94 149.4 0.69596 E94
95 137.37 0.61067 E95
96 133.64 0.49802 T6
97 125.44 0.39521 E97
98 114.09 0.33601 E98
99 128.89 0.71847 E99
100 119.61 0.6198 E100
101 120.68 0.50937 E101
102 107.45 0.40397 E102
103 96.616 0.31392 E103
104 87.023 0.226 C4
105 75.432 0.14773 E105
106 38.134 0.073411 E106
107 111.71 0.72392 E107
108 104.33 0.5265 T4
109 89.751 0.41016 E109
110 76.923 0.30135 E110
111 60.468 0.22774 E111
112 36.815 0.15618 E112
113 86.215 0.74376 E113
114 79.414 0.65035 E114
115 83.259 0.53862 E115
116 66.491 0.39953 E116
117 53.144 0.31263 E117
118 36.759 0.26161 E118
119 69.431 0.78544 E119
120 69.655 0.70597 E120
121 61.131 0.63414 E121
122 57.179 0.51491 E122
123 46.179 0.38996 E123
124 36.524 0.33208 F4
125 53.521 0.66717 E125
126 29.38 0.72532 E126
127 -29.38 0.72532 E127
128 -53.521 0.66717 E128

You should be able to upload a file of size 40MB to the forum. If not, please post the error message.

Juergen