Dear Roy,
Thanks a lot for your reply. I will try to write a basic solver first and
test those approaches. Then I can discuss with you guys what I find there.
Sincerely Yours,
Lei Shi
----------
On Wed, Aug 29, 2012 at 4:45 PM, Roy Stogner <royst...@ices.utexas.edu>wrote:
>
> 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
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