Keep proper Indexing after sorting

I have a matrix like below

 fset(:,:,1) = rand(5,16); 
 fset(:,:,2) = rand(5,16);
 fset(:,:,3) = zeros(5,16);
 sorted_fset = sort(fset,3);

My problem is i have 999 small matrix in a big matrix like this means

 fset(:,:,i),i=1,2,3,4....999

I represent the each image actually, now when i sort the matrix it sort for me but i cannot recognize the index of each image.

Like in above case

 fset(:,:,3) will be fset(:,:,1)

but actually it was 3, so how i can recognize the image index after sorting in this case. if any confusion please comment

Answer 1

[Jan]

[sorted_fset, index] = sort(fset, 3);

Matlab offers an exhaustive documentation which should be read in case of difficulties:

help sort
doc sort

[M@lik Ali]

I tried to read from matlab help

i try this one, but how i can get the corresponding index from this.

[Jan]

I do not understand your comment. I've posted the method to get the sorting indices as 2nd output already. This method is explained in the mentioned help text also. So what are you looking for now?