[Eeglablist] a question about SPECTOPO function

[fanz at psy.gla.ac.uk]

Hi everyone,

I used the SPECTOPO function to calculate the contribution of all  
components in a certain channel at the selected frequency. I checked  
the code in EEGlab:

  [spectra,freqs,speccomp,contrib,specstd] = spectopo(data, frames,  
srate, 'key1','val1', 'key2','val2' ...);

and the 'contrib' should be the result I look for.

However, when I use the graphical interface of EEGlab by select  
'plot-> component spectra and maps', and it will print the following  
information:

Computing component spectra:  (window length 256; fft length: 512; overlap 0):
.........................
Component 1 percent relative variance: 31.32
......

  I need to save these contributions, but I can't find the contrib in  
the workspace.

When I choose the appropriate parameters and run the command  
'[spectra,freqs,speccomp,contrib,specstd] = spectopo(data, frames,  
srate, 'key1','val1', 'key2','val2' ...);', and the result is strange.

data: 25 (channels) X 750 (frames per epoch) X 130 (epochs)
strate: 250
weight matrix is 25  X25 ,

so the contrib shoule be the matrix which size is 25 X 1. However, the  
result is the matrix which size is 25 X 257.

So can anyone help me?

Cheers

Fan Zhang



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