change discretization algorithm to do one operator at a time
Discretization algorithm will need to be change to follow simpler work of discretizing with one opeartor at once. Consider following
kx**2 * A * kx**2 * ky
Current discretization with kx**2 * ky
will already give short hoppigns on x-direction once kx**2
on the left side will not.
Priority: medium
Note: Can be done separately from redesigning recursive algorithm.