sensor numbers on topoplot

[Sameer Walawalkar]

Hello,

While using topoplot, if one uses

cfg.electrodes = 'numbers';
you get a plot with the sensor number written over each of the sensor
positions. What do these numbers correspond to?

If I look at NM306 layout diagram and locate sensor 2121 (on the midline
at the very bottom of the occipital lobe), this corresponds to a sensor
number 289 on the topoplot.

Yet if I do
cfg = [];
cfg.layout           = 'NM306all.lay';
lay = prepare_layout(cfg)
reading layout from file NM306all.lay

lay =

        pos: [308x2 double]
      width: [308x1 double]
     height: [308x1 double]
      label: {308x1 cell}

>> lay.label(289)

ans =

     '2533'

>> find(strcmp(lay.label,'2121'))

ans =

    240

Can someone help me understand this?
This is necessary to understand how to assign cfg.highlights.


Thanks,
sameer

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