From: Michael Orlitzky Date: Tue, 16 Oct 2012 02:16:13 +0000 (-0400) Subject: Negate the poisson matrix during its generation. X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=2fbcf94908d646ec62d2f15f7ec35288c6ac1cfe;p=octave.git Negate the poisson matrix during its generation. --- diff --git a/poisson_matrix.m b/poisson_matrix.m index 696185f..4171374 100644 --- a/poisson_matrix.m +++ b/poisson_matrix.m @@ -60,6 +60,7 @@ function A = poisson_matrix(integerN, x0, xN) A = cat(1, A, u_row); end - ## Finally, append the last row for xN. - A = cat(1, A, u_xN_coeffs); + ## Finally, append the last row for xN and negate the whole thing (see + ## the definition of the poisson problem). + A = - cat(1, A, u_xN_coeffs); end