I am looking for a code to solve a nine-point finite-difference representation which arising from an elliptic PDE with cross-derivitive.

A1(I,J)*F(I-1,J-1) + A2(I,J)*F(I ,J-1) + A3(I,J)*F(I+1,J-1)

+ A4(I,J)*F(I-1,J ) + A5(I,J)*F(I ,J ) + A6(I,J)*F(I+1,J )

+ A7(I,J)*F(I-1,J+1) + A8(I,J)*F(I ,J+1) + A9(I,J)*F(I+1,J+1)

= Q(I,J) Does anyone have it in hand or know where I can get it? For the algorithm, the Strongly Implicit Procedure of Stone(1968, SIAM J. Numer. Anal., vol.5, 530-9) is preferred but other is also welcome. I know the Modified Strongly Implicit (MSI) procedure (Schneider & Zedan, 1981, Numer. Heat Transfer, vol.4,1-19). Is there one here who knows it? Any information is appreciated.

Zhong

SIP is in the NAG library, which is not in the public domain. A SIP code is also (freely available) in the code which accompanies the book by Ferziger and Peric (Springer Verlag ISBN 3-540-59434-5). There is SIP for 2D and 3D problems (though only 5 and 7 points moleculs) and vectorized 3D version. To get the code: 1) ftp to ftp.springer.de 2) cd pub/technik/peric 3) get read.me and read the instructions there