Dear Jonathan, For example my smallest dimension in the mesh is a circle with diameter 6μ (E-06). (where in order to get good results I have to define cellsizes of 1E-07) Now about the Gmsh2D I use a .msh generated file and import it do you think it would be better to do it this way? Thank you very much in advance! Regards, J.
On Mon, Aug 26, 2013 at 7:36 PM, Guyer, Jonathan E. Dr. < [email protected]> wrote: > > On Aug 26, 2013, at 10:17 AM, Daniel Wheeler <[email protected]> > wrote: > > > I've also had issues with small meshes in Gmsh. This is obviously a > completely dumb problem. The absolute length scale of the mesh should have > no bearing on Gmsh's outcome. Anyway, in the past I've just scaled the > problem up so that the grid spacing is ~1. You can then rescale the mesh in > FiPy or rescale the equations. > > This can be an issue, but I'm not clear that it is here. The problems I > usually look at have features on the order of nanometers to micrometers. 2 > cm x 1 cm sounds astronomical to me. One question is what units are you > using? In CGS, then your mesh is order 1 as advocated by Daniel. Even in > MKS, I can specify sub-nanometer grid spacings without much difficulty. > > > On Aug 24, 2013, at 10:07 AM, John Assael <[email protected]> wrote: > > > Could you please kindly suggest me any settings that could balance > precision and performance for such a small size? > > You can solve at some uniform resolution and then if you can calculate an > error metric for that solution (there are a variety of ways and they depend > on what you're calculating), then you can use that error metric to scale > the mesh by passing a "background=" argument. See the end of the docstring > at > http://www.ctcms.nist.gov/fipy/fipy/generated/fipy.meshes.html#fipy.meshes.gmshMesh.Gmsh2D > > > > > > _______________________________________________ > fipy mailing list > [email protected] > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] > -- ..:: ic3man.gr ::.. software | design | development _/_/_/ email: [email protected] _/_/_/ www : http://www.ic3man.gr ------------------------------------------------------------------ This e-mail and any attachments are confidential. You may not copy or disseminate any information contained in them to anyone other than the intended recipient. If you are not the intended recipient please contact the sender by reply e-mail and destroy all copies of the original message immediately. ------------------------------------------------------------------
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