On Monday March 14 2011 10:25:10 Anders Logg wrote: > On Mon, Mar 14, 2011 at 09:06:00AM -0700, Johan Hake wrote: > > On Monday March 14 2011 08:44:19 Neilen Marais wrote: > > > Johan, > > > > > > On Mon, Mar 14, 2011 at 5:21 PM, Johan Hake <[email protected]> wrote: > > > > On Monday March 14 2011 04:36:29 Neilen Marais wrote: > > > > If you have an already tetrahedralized structure, typically given by > > > > a coordinate array and an array of conductivities between cells and > > > > vertices, you can use MeshEditor. That is what MeshEditor really is > > > > for. > > > > > > > > > > > > I think the advice of not using MeshEditor is when you use it to > > > > construct the vertices and connectivities by hand. > > > > > > I guess I'm just worrying about performance in python, since I would > > > have to do one method call for each vertex and one for each tet. I may > > > be prematurely optimising here, but IIRC even method calls to SWIG > > > wrapped C++ classes have a fair amount of overhead. Since I already > > > have the vertex coordinates and cell -> vertex connectivity data in > > > arrays, it is obviously much faster to just stuff them directly into > > > the dolfin structures? > > > > Sure you are right that it might come with some overhead. Not sure it > > will be significant though, as this would probably be a one time thing? > > > > But after reading your post one more time I realize what you asked for > > :P, and the answer is yes! You can perfectly do what you did. > > mesh.cells() and mesh.coordinates() each return a NumPy array view of > > the actuall data. Your syntax works because NumPy allows it. > > It works because it happens to work. It's not intended usage and it > might break if we change the implementation MeshEditor, even if the > interface stays the same. > > It would be better to add some utility function for creating a Mesh > based on arrays.
I agree. But as long as we store the coordinates and cells as contiguous arrays in the mesh, they will be exposed to Python through NumPy and this will just work. Johan > -- > Anders > > > I would do this in a separate script once for each mesh, and then save it > > to file so you do not have to do this each time you read in a mesh. > > > > > > > > Johan > > > > > > Johan > > > > > > Best regards > > > Neilen > > > > > > _______________________________________________ > > > Mailing list: https://launchpad.net/~dolfin > > > Post to : [email protected] > > > Unsubscribe : https://launchpad.net/~dolfin > > > More help : https://help.launchpad.net/ListHelp > > > > _______________________________________________ > > Mailing list: https://launchpad.net/~dolfin > > Post to : [email protected] > > Unsubscribe : https://launchpad.net/~dolfin > > More help : https://help.launchpad.net/ListHelp > > _______________________________________________ > Mailing list: https://launchpad.net/~dolfin > Post to : [email protected] > Unsubscribe : https://launchpad.net/~dolfin > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
