plots and stats with biosemi128.lay

Katya Vinnik lulswinnik at GMAIL.COM
Mon Mar 23 19:19:23 CET 2009

Dear FT users,

has anyone of you encountered this warning?
Duplicate x-y data points detected: using average of the z values.

I'm simply plotting my data with
cfg.layout 	= 'biosemi128.lay';

and it gives me strange plots like the one here:

basically data from channels B19 and 21 and D22 and 24 are overlayed
(circled in red on the pictures).
This message appears also with topoplot functions. In the layout file,
howether ,positions of this electrodes are different (see below).

Do you think it can affect cluster-based multiple comparison correction?

For example, if I use

cfg.layout 	= 'biosemi128.lay';
cfg.correctm = 'cluster';
 [stat] = freqstatistics(cfg,x,y)

does it calcultate it properly?

Thank you,
Best regards,

P.S. positions of this electrodes from biosemi128.lay:

    51	0.521467	-0.301069	0.180000	0.140000	B19
    53	0.602139	0.000000	0.180000	0.140000	B21
    118	-1.404990	-0.000000	0.180000	0.140000	D22
    120	-1.527114	-0.496189	0.180000	0.140000	D24

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