getoperatordiagonalinverse(preconditioner)

Compute or retrieve the inverse of the symbol matrix diagonal for a Jacobi

Returns:

• symbol matrix diagonal inverse for the operator

Example:

# setup
mesh = Mesh1D(1.0);
diffusion = GalleryOperator("diffusion", 3, 3, mesh);

# preconditioner
jacobi = Jacobi(diffusion);

# verify operator diagonal inverse
@assert jacobi.operatordiagonalinverse ≈ [6/7 0; 0 3/4]

# output