Tridiagonal Block Matrix Using Scipy.sparse

I need help in building a block tridiagonal matrix using scipy sparse. What I mean by that is for a square matrix B, I need to create [[B I 0 0 0] [I B I 0 0] [0 I B I 0] [0 0

Solution 1:

Solved it!

I just used scipy.sparse.bmat in conjunction with list comprehensions.

A = sparse.bmat([[B if i == j else np.eye(n) ifabs(i-j)==1elseNonefor i inrange(n)]
                for j inrange(n)], format='bsr')

Where B is an nxn matrix.