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On 29/06/10 14:33, Mehdi wrote:
On Tue, 2010-06-29 at 12:13 +0200, Anders Logg wrote:On Tue, Jun 29, 2010 at 11:50:38AM +0200, Mehdi wrote:Is there any specific reason why we have this type of problems in resizing uBLAS vectors not other type of vectors?Yes, because of a bug in the uBLAS resize function (it does not initialize data).Note that resizing a vector becomes important in the adaptive methods. Since when a function updates, we need to resize its underlying vector. If we clear a vector, then we lose all data that we had there.There's no point in keeping the old dofs as part of the vector since the number of the mesh (and the old dofs) may change. What is needed for adaptive methods is to interpolate the old solution to the new mesh (which is already implemented in DOLFIN).This is not the case in XFEM where we have a fixed mesh but the number of degrees of freedom is changing. Although this is not a big challenge, since we can define some local variables to transfer data from the old vector to new one.
No all backends support preservation of data when resizing, so it's not an option to preserve data when calling GenericVector::resize.
Garth
Mehdi-- AndersMehdi On Mon, 2010-06-28 at 15:01 +0000, Anders Logg wrote:The problem was that x = Vector(b.size()) created a vector which sometimes contained strange numbers. This has been changed now (in uBLASVector::resize()) so that the vector is always zero. Took me a while to work through all the 29 different axpy_prod that call each other in operation.hpp in uBLAS... Should be fixed now. ** Changed in: dolfin Status: Confirmed => Fix Committed_______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@xxxxxxxxxxxxxxxxxxx Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp_______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@xxxxxxxxxxxxxxxxxxx Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
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