Discrete Poisson equation: Difference between revisions

→‎On a two-dimensional rectangular grid: We need to switch sign of b, though, if we switch sign of A and D
(→‎On a two-dimensional rectangular grid: The definition of the laplacian has still the wrong sign)
(→‎On a two-dimensional rectangular grid: We need to switch sign of b, though, if we switch sign of A and D)
:<math>
b =
-\Delta x^2\begin{bmatrix} g_{11} , g_{21} , \ldots , g_{m1} , g_{12} , g_{22} , \ldots , g_{m2} , \ldots , g_{mn}
\end{bmatrix}^T.
</math>