Hello,

I have a matrix defined on a mesh as given below.

I want to make it into a larger system by placing my matrix a into a block matrix

My attempt is [code] a = BilinearForm(fes)

a += grad(u)*grad(v)*dx

length = a.mat.height

Z = sp.coo_matrix((length, length))

I = sp.identity(length)

B1a = sp.hstack([a.mat, Z])

B1b = sp.hstack([Z, I])

B1 = sp.vstack([B1a, B1b])[/code]

however this results in the following error message:

blocks[0,:] has incompatible row dimensions. Got blocks[0,1].shape[0] == 358240, expected 1.

How to I get around this error