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Re: Irregularly gridded Discrete Laplacian Operator
From: |
Marco Caliari |
Subject: |
Re: Irregularly gridded Discrete Laplacian Operator |
Date: |
Thu, 19 Jul 2007 11:14:29 +0200 (CEST) |
On 18/07/07, David Bateman <David.Bateman at motorola.com> wrote:
> whereas the equivalent in Matlab appears to be
>
> D(2:end-1) = ((M(3:end) - M(2:end-1)) ./ dx(2:end) + (M(1:end-2) -
> M(2:end-1)) ./ dx(1:end-1)) ./ (dx(1:end-1) + dx(2:end))
A factor 2 is missing. In any case, it is a first order approximation of
the second derivative. Better approximations can be obtained by taking a
larger stencil, see, e.g.,
http://www.damtp.cam.ac.uk/user/na/PartII/Lect15.pdf
Best regards,
Marco