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matlabmatrixsparse-matrix

Create a matrix from some given matrices

I have this matrix to implement. Where user would define the value of dimensions ( p and N).

matrix

what would be the most efficient way to doing this in matlab.

Solution

  • assuming you have a function to define A(p), B(p), and C(p) you can use kron as follows:

    F = @(N,p) kron(diag(ones(N,1)),A(p)) + ... 
           kron(diag(ones(N-1,1),1),B(p)) + ...
           kron(diag(ones(N-1,1),-1),C(p))

    For example, if 

    A = @(p) ones(p);
B = @(p) 2*ones(p);
C = @(p) 3*ones(p);



>> F(4,2)

ans =

 1     1     2     2     0     0     0     0
 1     1     2     2     0     0     0     0
 3     3     1     1     2     2     0     0
 3     3     1     1     2     2     0     0
 0     0     3     3     1     1     2     2
 0     0     3     3     1     1     2     2
 0     0     0     0     3     3     1     1
 0     0     0     0     3     3     1     1