<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Oct 8, 2012, at 2:11 PM, Jed Brown <<a href="mailto:jedbrown@mcs.anl.gov">jedbrown@mcs.anl.gov</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">On Sun, Oct 7, 2012 at 11:59 AM, Alan <span dir="ltr"><<a href="mailto:zhenglun.wei@gmail.com" target="_blank">zhenglun.wei@gmail.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div>Dear Dr. Brown, <br>
I was trying to use PETSc to mimic something like Chombo. The
figure in this website represents my thought very well. (<a href="https://commons.lbl.gov/display/chombo/Chombo+-+Software+for+Adaptive+Solutions+of+Partial+Differential+Equations" target="_blank">https://commons.lbl.gov/display/chombo/Chombo+-+Software+for+Adaptive+Solutions+of+Partial+Differential+Equations</a>).
My code simulates a flow over a objective, i.e. 2D cylinder. Finer
resolution is needed near the objective. I can manually define
where the finer resolution is needed.<br></div></div></blockquote><div><br></div><div>You could just use Chombo... It's a lot of work to write a good implementation of dynamic AMR. We don't have a fully worked example of doing that, but there are plenty of packages that do AMR and use PETSc.</div></div></blockquote><div><br></div><div>You should also consider BoxLib, which comes from the same hallway at LBNL and both projects are lead by a member of the NAS. BoxLib is less C++ and it has a more sophisticated interface to PETSc (better than mine from what I know). Chombo has support for multi block grids and embedded boundaries. I've worked a lot with Chombo and it is a nice product but there is definitely a learning curve, especially if you are not experienced with C++. I've not worked with BoxLib but I'm sure it is good also.</div><div><br></div><div>Mark</div><br><blockquote type="cite"><div class="gmail_quote">
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BTW, I wonder if there is any examples for the Vec/Mat
interface.</div></blockquote><div><br></div><div>See src/mat/examples/tutorials, or any of the higher level interfaces. Look at the user's manual.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> Also, is there any examples for PETSc for GPU. </div></blockquote><div><br></div><div><a href="http://www.mcs.anl.gov/petsc/features/gpus.html">http://www.mcs.anl.gov/petsc/features/gpus.html</a></div>
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<br>
thanks,<br>
Alan<br>
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<blockquote type="cite">On Sat, Oct 6, 2012 at 10:47 PM, Alan <span dir="ltr"><<a href="mailto:zhenglun.wei@gmail.com" target="_blank">zhenglun.wei@gmail.com</a>></span> wrote:<br>
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<div>Dear Dr. Brown, <br>
Thanks for your reply and sorry for confusing you. <br>
I was trying to ask if there is an alternative way
that I can replace the DMDACreate3d in
/src/ksp/ksp/example/tutorials/ex45.c with something from
outside of the PETSc (i.e. HYPRE). DMDACreate3d generates
a 3D Cartesian grid with uniform grid size. However, I'm
trying to import a local refined grid from outside of the
PETSc (i.e. HYPRE) to replace this 3D Cartesian grid with
unifrom grid size. Is there any examples for me to refer?<br>
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<div>Do we have automatic support for this? No. You could of
course just use the Vec/Mat interface, but</div>
<div>
it sounds like a lot of coding on your part. I plan to do this
eventually by specifying the data layout over</div>
<div>the grid using PetscSection. However, the really important
question here is, what do you need from the</div>
<div>grid? If you don't need topological queries, just make the
Vec/Mat and be done with it. If you do (which</div>
<div>I imagine), then you need to be specific about what you
need.</div>
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<div> Matt</div>
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<div> thanks,<br>
Alan<br>
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<blockquote type="cite">Run any example with -pc_type hypre.
I'm not sure what you're asking for.<br>
<br>
<div class="gmail_quote">On Sat, Oct 6, 2012 at 8:04 PM,
Alan <span dir="ltr"><<a href="mailto:zhenglun.wei@gmail.com" target="_blank">zhenglun.wei@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Dear
Folks,<br>
I hope you're having a nice day.<br>
I'm trying to couple HYPRE with PETSc in order to use
PETSc solvers to<br>
obtain solutions (Poisson Equation) with local refined
grid from HYPRE.<br>
Is there any examples in PETSc that I can refer? or is
there any<br>
examples in PETSc which introduce such a way that the
Matrix is imported<br>
from external software rather than generated by PETSc.<br>
<br>
thanks,<br>
Alan<br>
<br>
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-- <br>
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to
which their experiments lead.<br>
-- Norbert Wiener<br>
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