Thread Subject:

Matrix form of Vector differences

Hi,

I know that for a Vector A: A'*A creates a Matrix of all the elements of A multiplied by each other.
Is there a similar method for adding/subtracting, without looping?
I guess you have to turn the Vector into a repeated matrix, and then find the sum/difference.

Thus far i have:
>> a = [1 2 3 4 5]

a =

     1 2 3 4 5

>> b = a'*ones(1,length(a))

b =

     1 1 1 1 1
     2 2 2 2 2
     3 3 3 3 3
     4 4 4 4 4
     5 5 5 5 5

>> c = ones(1,length(a))'*a

c =

     1 2 3 4 5
     1 2 3 4 5
     1 2 3 4 5
     1 2 3 4 5
     1 2 3 4 5

>> c-b

ans =

     0 1 2 3 4
    -1 0 1 2 3
    -2 -1 0 1 2
    -3 -2 -1 0 1
    -4 -3 -2 -1 0


Is there a better / less verbose method?

Zeph

Scratch that, just found it:

bsxfun(@minus,a,a')