function [MeanAmp] = mean_amp(Datastack,t1,t2,pre)
% finds the mean amplitude of the data with the range t1:t2
a = t1+pre;
b = t2+pre;
MeanData = mean(Datastack);
MeanData = permute(MeanData,[2,3,1]);
MeanAmp = mean(MeanData(a:b,:));
MeanAmp = permute(MeanAmp,[2,1]);
end