sparse mtrix from sparse matrices

Hi

I have three matrices (a, h and k1) like:

a =

   (1,1)        1
   (2,2)        1
   (3,3)        1
   (4,4)        1
   (5,5)        1
   (6,6)        1
   (7,7)        1
   (8,8)        1
   (9,9)        1

>> h=sparse(n3,n3)

h =

   All zero sparse: 9-by-9

>> k1=-4*a

k1 =

   (1,1)       -4
   (2,2)       -4
   (3,3)       -4
   (4,4)       -4
   (5,5)       -4
   (6,6)       -4
   (7,7)       -4
   (8,8)       -4
   (9,9)       -4

I want to create a matrix from these matrices in this form that is sparse.

q=['k1' 'h' 'a' 'h'; 'h' 'k1' 'h' 'a']

How can create that please?

[fatema saba]

Hi

I can find it. it is something like that:

q=sparse([k1,h,a,h;h,k1,h,a])

[the cyclist]

I think the concatenation of sparse arrays is sparse, so you probably don't need that sparse command.