DA with imposed parallel decomposition

[Barry Smith]

   This is a bug, we need to capture it in a debugger somehow. If you  
can reproduce it in something we can run then we'll debug it.


   Barry

On Sep 23, 2009, at 8:07 AM, Dave May wrote:

> Sorry Barry,
>   I should have been more specific. I get a segmentation violation.
> I think writing a simple test to isolate the bug is the best option  
> to debug this error.
> Do you agree?
>
> Cheers,
>   Dave
>
>
> On Wed, Sep 23, 2009 at 3:00 PM, Barry Smith <bsmith at mcs.anl.gov>  
> wrote:
>
> On Sep 23, 2009, at 7:47 AM, Dave May wrote:
>
> Hey Matt,
>    In one piece of code I have, yes the call to DAGetInterpolation()  
> does seem to cause a nasty crash.
>
>   A crash? Segmentation violation etc? Or an error message saying  
> that the decomposition is not supported? They are very different  
> things: a crash is a bug we need to deal with, unsupported is just  
> because it is too hard to support refinement with all decompositions.
>
>   Barry
>
>
> It doesn't occur all the time, just with certain processor sizes  
> (64) and certain mesh sizes (80x80x40). I was wondering if there was  
> some pathological cases I did not know about.
>
> I think I will have to write a stand alone test case to see if I can  
> reproduce the error in a simpler code.
> I don't think what I'm doing should cause a problem, but I'm not  
> sure how best to debug the problem I have.
>
> Any hints would be appreciated.  :)
>
> Cheers,
>  Dave
>
>
>
> On Wed, Sep 23, 2009 at 2:33 PM, Matthew Knepley <knepley at gmail.com>  
> wrote:
> Since it just inserts a point on every edge and face (in 2D), I do  
> not see why it would fail. Does it?
>
>  Matt
>
>
> On Wed, Sep 23, 2009 at 12:04 AM, Dave May <dave.mayhem23 at gmail.com>  
> wrote:
> Hello,
>  Suppose I have a DA and I enforce the parallel decomposition during  
> creation by specifying the arrays lx[], ly[], lz[] in DACreate3d().  
> If I now create a second DA using DARefine(), am I alays also able  
> to obtain an interpolation operator between the two DA's via  
> DAGetInterpolation()?
>
> Under what circumstance will DAGetInterpolation() fail when used  
> between DA's generated in this manner?
>
> Cheers,
>  Dave
>
>
>
>
> -- 
> What most experimenters take for granted before they begin their  
> experiments is infinitely more interesting than any results to which  
> their experiments lead.
> -- Norbert Wiener
>
>
>