Jed-- > ... > > I guess I would want the loop to be replaced by > > "DAVecScaleDOF(da,v,k,alpha)" for k=0,...,dof-1. > > It's spelled VecStrideScale(). > > > Same question for VecNorm: norm just an identified component? > > You guessed it, VecStrideNorm()
RIght! Sorry to miss that. Didn't search on "Stride". > But, I actually recommend nondimensionalizing ... so that these component > norms are not needed by the solvers, as the nondimensional system will > generally produce a better conditioned algebraic system. Did not need the norm for the solvers, actually. I wrote a scaling/descaling "shell" around the residual evaluation routine, so the latter could be dimensional. At this early, prototype stage, where I am at on my code, I don't want the "clutter" of nondimensionalizing PDEs if I am familiar with them in dimensional units. > ... nondimensionalizing (in the sense of ex48, not in terms on > nondimensional numbers ...) ... ex48.c is heavy-going if what one wants is an example showing how PETSc can help with scaling the residual and Jacobian for better conditioning. Related question: Is it true that an instance of DALocalFunction1 will cause trouble if it modifies the solution array? (The values supplied in the "Field *u" argument?) It seems that this is so, which I did not expect for this call-back. Related comment: There is no man page on DALocalFunction1, I think. Thanks! Ed -- ********************************** Ed Bueler 474-7693? ?? (fax 474-5394) Dept of Mathematics and Statistics 301C Chapman Hall, Univ of Alaska Fairbanks, AK 99775-6660 www.dms.uaf.edu/~bueler **********************************
