On Wed, 29 Aug 2012, Lei Shi wrote:
I will do some experiments to compare the results based on computing
every cheap thing when needed and store everything needed.
Let us know the results! Speculating about optimization ideas is a
poor substitute for profiling optimization ideas.
The other question is the element iterator. When we write ++iter,
what happened behind this operator? Does the current element need to
climb along the quad forest and go down to the lowest child? Can we
just construct a map with all active elementIndex -> element *
mappings? and directly use this map or vector to loop the elements.
In a SerialMesh, ++iter just increments through an STL vector,
potentially testing predicates (e.g. whether an element is active)
along the way. ParallelMesh is similar but with a STL map under the
hood.
Searches through a quadtree/octree only happen when using a
PointLocator object, and most library code doesn't use those. The big
exception is with PeriodicBoundary support; Derek or the other INL
people could tell you whether or not that turns out to be a
performance hit.
I know there is no anisotropic refinement in the lib. How much
effort I need to put to add anisotropic? I mean how many percent the
current code based on those isotropic assumption?
For starters, "egrep '(->|\.)level\(*/*/*.{C,h} | wc" shows about a
hundred lines of code, the majority of which are implicitly assuming
that the idea of an isotropic "refinement level" makes sense. Fixing
that to enable non-conforming anisotropic refinement would be a
serious effort.
Conforming anisotropic refinement might not be too bad. Add the right
edge splitting algorithms for triangles and tets, don't bother
creating a tree structure, and you could get solutions without
changing anything else. You'd want to create a new project_vector()
codepath to get efficient solutions.
---
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-devel mailing list
Libmesh-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/libmesh-devel
