On Sat, May 14, 2011 at 3:25 PM, Jed Brown <jed at 59a2.org> wrote: > On Sat, May 14, 2011 at 22:21, Barry Smith <bsmith at mcs.anl.gov> wrote: >> >> The user will be composing preconditioners on splits etc using the string >> name (you cannot type an IS at the command line but you can type "pressure") >> so I am not sure why you are so focused on "the IS _is_ the thing you need". >> So I can see the string names as being important. > > I assumed fieldsplit would use the string name and then hold onto the IS > (there is a good chance it is needed internally anyway). I don't see why the > string name would be needed in a performance-sensitive place since it's only > for "configuration" anyway. So the splits are identified by the IS (e.g., "give me the subvec corresponding to the split with this IS")? I assume that will require IS matching. Is that faster than string matching (I guess it depends on the string/IS length/type).
Dmitry.
