B = repmat(A,m,n)
B = repmat(A,[m n])
將A矩陣看作元素，復制組成m行n列，即將A復制m*n個
>> A = [1,2;3,4]
A =
1 2
3 4
>> B = repmat(A,2,3)
B =
1 2 1 2 1 2
3 4 3 4 3 4
1 2 1 2 1 2
3 4 3 4 3 4