On Thu, Aug 07, 2008 at 10:32:56PM +0100, Garth N. Wells wrote: > Something I don't understand is the time for creating the sparsity > pattern for MTL4 when it involves no operations?
MTL4Factory still returns a sparsity pattern. I wasn't aware that MTL4 didn't need one. MT4Factory should return 0 in createPattern() and MTL4SparsityPattern can then be removed. I can fix this later today if you don't fix it before. > Why is uBLAS now faster than before (relative)? I didn't notice. I might have made an apt-get upgrade in between. I don't think anything has changed for uBlas in the code. -- Anders > Garth > > Anders Logg wrote: > > I have made some changes to allow a backend to notify that it does not > > need to be initialized by a sparsity pattern. If the factory function > > createSparsityPattern() returns 0, then the assembler will not build > > the sparsity pattern. > > > > I have tried this for the STL backend (earlier called AssemblyMatrix). > > No sparsity pattern is computed and no preallocation is made, just > > inserting directly into the vector of vectors using a linear search > > and this gives very good speedups, see here: > > > > http://www.fenics.org/wiki/Benchmark > > > > STL is 36% faster than all other backends for the NS testcase. > > > > It is also about just as fast as the other backends for the assembly > > step ("Assemble cells") even if no preallocation is made. > > > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > DOLFIN-dev mailing list > > [email protected] > > http://www.fenics.org/mailman/listinfo/dolfin-dev > _______________________________________________ > DOLFIN-dev mailing list > [email protected] > http://www.fenics.org/mailman/listinfo/dolfin-dev
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