MATLAB: Wrong way to index: Index exceeds matrix dimensions

Question

Hi,

I'm trying to use indices to expand a vector but I keep getting an error message and I don't understand why. In particular, what I'm trying to do works in an example such as

x=[1 2 3]';
y=[.1 .5 .3]';
z=[1 1 2 2 3];
yz=y(z);

Here I have two vectors, x and z that have the same values for the indices. I want to expand the vector y to have the same dimensions as z but the values of z must be repeated according to how the index is repeated.

Now, in my application this is not working. I have two vectors X and Z, X of dimensions 2270×1 and Z of dimensions 446723×1 that contains the same indices as X but a lot of times (and each number is repeated a different number of times). To check that the indices are the same I used isequal(unique(X),unique(Z)) and the output was 1.

Finally, I have a vector Y of dimensions 2270×1 that plays the role of y in the example above. When doing YZ=Y(Z) I get ??? Index exceeds matrix dimensions.

Any ideas what is going on?

Thanks,

Answer 1

max(Z) is greater then 2270?