Problems with ttest function

Hello,

I've been trying to use the ttest function to compute a paired ttest between power values obtained from EEG (pre vs post) using the following function:

pval = 0.05 [h, p, ci, stats] = ttest(EEG1, EEG2, pval);

and

[h, p, ci, stats] = ttest(squeeze(EEG1), squeeze(EEG2), pval);

But it gives me the same error:

Undefined function or variable 't'.

Error in nanmean (line 7) N = sum(~isnan(t), dim);

Error in ttest (line 131) xmean = nanmean(x,dim);

Is this because the NaN function is not working? If so, does anyone know how to fix it?

Best regards,

Christian

Answer 1

[Star Strider]

What are the dimensions of ‘EEG1’ and ‘EEG2’? What is the result of isnan on both arrays?

I would start by plotting ‘EEG1’ and ‘EEG2’ as functions of frequency on the same plot, then doing nanmean of both, since that seems to be where the problem is.