On Mon, 17 Sep 2012, David Knezevic wrote: > On 09/17/2012 01:33 PM, Roy Stogner wrote: >> That's good to keep in mind. PETSc performance (at least in the older >> versions where I've made this mistake) becomes atrocious if it's asked >> to create new non-zero matrix entries on the fly without >> preallocation. > > Presumably MatMatMult in PETSc (or the equivalent in trilinos) handles > this in some sensible way though.
Sensible in the sense that "ask the user to estimate the ratio nnz(A*B)/(nnz(A)+nnz(B))" is probably the least bad of a bunch of bad alternatives. That's kind of a quirky thing to try and encapsulate in a non-solver-specific API, though... --- Roy ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
