MATLAB: Subtracting matrix subsets by specific rows

Question

Here is an example of a subset of the matrix I would like to use:

1 3 5

2 3 6

1 1 1

3 5 4

5 5 5

8 8 0

Answer 1

Here's another way to implement this with bsxfun, slightly different from natan's bsxfun implementation -

t1 = reshape(a,3,[]); %// a is the input matrix
out = reshape(bsxfun(@minus,t1,t1(1,:)),[],3); %// Desired output