> However, I'm not sure why there is a preset argument and why it defaults > to false.
This is what the last paragraph of the documentation you cited wanted to explain: ------------------------- Despite the fact that it would seem to be an obvious win, setting the preset_nonzero_locations flag to true doesn't seem to accelerate program. Rather on the contrary, it seems to be able to slow down entire programs somewhat. This is suprising, since we can use efficient function calls into PETSc that allow to create multiple entries at once; nevertheless, given the fact that it is inefficient, the respective flag has a default value equal to false. ------------------------ This was written when PETSc 2.2 was current, so it may have changed in the meantime. If you think the default value should be changed, would you mind removing this hunk of documentation? Best W. ------------------------------------------------------------------------- Wolfgang Bangerth email: [email protected] www: http://www.math.tamu.edu/~bangerth/ _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
