[Insight-developers] Re: Problems with new registrationoptimizations

[Bill Lorensen]

Stephen,

Actually, the error also occurs in ::TransformPointWithDerivatives...

Bill

On Dec 3, 2007 1:31 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:

> Stephen,
>
> Actually, in this case, there are still errors in the optimized
> implementation. I have compiled itk under g++ with the flags:
> CMAKE_CXX_FLAGS:STRING=-Wall -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC
> This causes all containers and iterators to check for a variety of
> violations. When I run the registration examples, they complain that in
> ImageToImageMetric::TransformPoint,
>  mappedPoint = transform->TransformPoint(
> m_FixedImageSamples[sampleNumber].point );
> sampleNumber exceeds the size of the container.
>
> I'm recompiling now and I'll send you a more detailed deception.
>
> Actually, if you add code like this:
>
>     if (sampleNumber >= m_FixedImageSamples.size())
>       {
>       itkExceptionMacro( << "sampleNumber " << sampleNumber << " exceeds "
> << m_FixedImageSamples.size() << " which is the container size of
> m_FixedImageSamples" << std::endl);
>       }
>
> just before the offending statement, the thrown exception will highlight
> the error.
>
> Bill
>
>
>
>
>
> On Dec 3, 2007 1:01 PM, Stephen R. Aylward < Stephen.Aylward at kitware.com>
> wrote:
>
> > This touches upon a developing topic: ITK consistency when run single
> > versus
> > multi-threaded.
> >
> > At this time, we have been able to relatively easily implement
> > algorithms so
> > that they produce the same results (i.e., have the same implementation
> > logic) when run single or multi-threaded.  This stability holds for the
> > new
> > multi-threaded registration framework.  Recall that this consistency
> > constraint has such small tolerance that it, for example, requires the
> > use
> > of a specific random seed with our implementation of a specific random
> > number generator for certain tests to pass.
> >
> > ISSUE: I am confident that we could continue to ensure the same
> > consistency
> > (e.g., make sure the same random number sequence is generated when run
> > single or multi-threaded) in all future work, but the complexity
> > introduced
> > if we must always maintain that extreme consistency is perhaps
> > detrimental
> > to multi-threaded algorithm efficiency and ease of understanding.
> >
> > PROPOSED SOLUTION: I propose that in the future we ALLOW the tolerance
> > needed for a test to pass to be adjusted, if that adjustment is needed
> > to
> > account for non-significant variations due to running the method single
> > vs.
> > multi-threaded.    The additional uncertainty/inconsistency in the
> > results
> > should not allow for variations in the interpretation of the
> > functionality
> > of the algorithm and should not allow for code errors to go undetected.
> >  The
> > additional uncertainty/inconsistency should allow, for examples, for
> > non-significant changes in results, where those changes are similar in
> > magnitude to what would be expected if a different random seed was used
> > in a
> > test.
> >
> > Agreed?
> >
> > Stephen
> >
> > =======================================
> > Stephen R. Aylward, Ph.D.
> > Chief Medical Scientist
> > Kitware, Inc. - Chapel Hill Office
> > http://www.kitware.com
> > Phone: (518)371-3971 x300
> >
> >
> > > -----Original Message-----
> > > From:
> > > insight-developers-bounces+stephen.aylward=kitware.com at itk.org
> > >
> > > [mailto: insight-developers-bounces+stephen.aylward=kitware.com
> > > @itk.org] On Behalf Of Matt Turek
> > > Sent: Monday, December 03, 2007 12:16 PM
> > > To: Bill Lorensen
> > > Cc: ITK
> > > Subject: [Insight-developers] Re: Problems with new
> > > registrationoptimizations
> > >
> > >
> > > Bill,
> > >
> > > I'll take a look at the failing tests. We've been focused on
> > > cleaning up the itk optimized dashboard.
> > >
> > > Matt
> > >
> > >
> > > Bill Lorensen wrote:
> > > > Matt,
> > > >
> > > > Looks like a crash in one of the metrics on those platforms
> > > that have
> > > > turned on the new optimizations:
> > > >
> > > http://www.itk.org/Testing/Sites/zion.kitware/Linux-g++-4.1/20071201-0
> >
> > > >
> > > 100-Nightly/Results/__Testing_Code_Algorithms_itkMattesMutualInformati
> > > > onImageToImageMetricTest.html
> > > >
> > > <http://www.itk.org/Testing/Sites/zion.kitware/Linux-g++-4.1/20071201-
> > > >
> > > 0100-Nightly/Results/__Testing_Code_Algorithms_itkMattesMutualInformat
> > > > ionImageToImageMetricTest.html>
> > > >
> > > > Also, 13 registration regression tests are failing on the optimized
> > > > registraion enabled gcc build:
> > > >
> > > http://www.itk.org/Testing/Sites/zion.kitware/Linux-g++-4.1/20071201-0
> > > > 100-Nightly/Test.html
> > > >
> > > > Should we expect the exact results?
> > > >
> > > > Bill
> > > >
> > >
> > > _______________________________________________
> > > Insight-developers mailing list
> > > Insight-developers at itk.org
> > > http://www.itk.org/mailman/listinfo/insight-developers
> >
> >
>
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