sorry this is a statistics question as well as a Matlab question...
i have two groups of data that i want to compare using ttest2. the two groups are independent. but among each group, there are some data-points that are dependent (because they come from the same samples).
so i guess that if i don't declare this, i get way more degrees of freedom (and hence significance) than what is "real". worst is, samples can be of very different sizes, and sometimes they can be huge (from 0 to more than 10000 data points per sample).
how can i declare to the ttest2 function that some data-points in both compared groups come from the same sample ? :-/