Are these the same equations you were asking about in https://github.com/usnistgov/fipy/issues/835? They seem closely related, but not identical, AFAICT.
Regardless, as explained there, you cannot mix higher-order diffusion terms with coupled equations. Can you show the equations you started with, before you started trying to put them in a form for FiPy? On Feb 8, 2022, at 12:44 PM, Matan Mussel <[email protected]<mailto:[email protected]>> wrote: Hello everyone, I am new to FiPy and interested in solving a certain curvature model. I thought using FiPy will make my life easier, but unfortunately I have been struggling with this for quite some time trying different versions of introducing the equations into FiPy. I decided to try this community, hoping to get some insight on what I am doing wrong. The model includes three variables (two dynamic, one auxiliary) and three coupled equations running on a 2D grid. Please see a summary of the model in the attached PDF file. I am also attaching a minimalistic version of the code. For this version the error message is: "[0] Matrix is missing diagonal entry 2500" (with 2500 being nx*ny). Many thanks in advance, Matan -- To unsubscribe from this group, send email to [email protected]<mailto:[email protected]> View this message at https://list.nist.gov/fipy --- To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. <CurvatureModelEquations.pdf><MinimalCurvatureModel.py> -- To unsubscribe from this group, send email to [email protected] View this message at https://list.nist.gov/fipy --- To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
