Combining 2 different sized matrices.

I am trying to learn and practice some Matlab, this is one of the test yourself questions and I am just not able to understand how exactly I can do this. If anyone is able to explain I will appreciate it. Thank you

Answer 1

[KSSV]

A = rand(3) ; 
B = rand(4) ; 
m = size(A,1) ; 
n = size(B,1) ; 
O1 = zeros(m,n) ; 
O2 = zeros(n,m) ; 
iwant = [A O1; O2 B] ; 

OR

A = rand(3) ; 
B = rand(4) ; 

m = size(A,1) ; 
n = size(B,1) ; 

C = zeros(m+n) ; 
C(1:m,1:m) = A ; 
C(m+1:end,m+1:end) = B ; 

[Dieter Ziemkendorf]

Thanks very much, I now see what i was doing wrong.