Susan, Others don't have your data sample1 and sample2 so won't be able to look at your data. Would the sign of lags(delay), be positive or negative, tell you whether Y is the delay of X, or X is the delay of Y?
In my answer to your previous question, http://www.mathworks.com/matlabcentral/answers/13110-signal-processing
y is 10 steps lag behind x, when running
[Rxx, lags] = xcorr(x, y);
[Y, I] = max(Rxx);
lags(I)
It returns -10, meaning y is 10 steps lag behind x
If you run
[Rxx, lags] = xcorr(y, x);%switch order of x and y
[Y, I] = max(Rxx);
lags(I)
It returns 10, meaning x is 10 steps ahead of y
