On Wed, Aug 13, 2008 at 8:08 PM, franck kalala <[EMAIL PROTECTED]> wrote: > I write a program and I got some plots, but these plots don't give what I am > expecting. here is my program: > I get some problem when the diffusion coefficient is a matrix and not a > scalar and the analytical solution is a function of x,y and t
Which version of fipy are you using? You should be aware of two things. 1) If you write the coefficient as "((0,1),(2,3))". This will be interpreted as a fourth order diffusion term. The first index refers to the order of the term. 2) Released versions of fipy (1.2 and earlier) do not have anisotropic diffusion (the diffusion term allows one to submit a matrix). You need to update to trunk in order to use this. To get what you want, you need to update to trunk (using subversion) and change your diffusion coefficient to be "(((0,1),(2,3)),)" for example. This will give you a second order diffusion term. If you miss out the final "," you will have a fourth order diffusion term with weird coefficients. Cheers -- Daniel Wheeler
