[vtkusers] ICP Error: vtkMath::Jacobi: Error extracting eigenfunctions

[David Gobbi]

Thanks for the info.  Can you post your compiler optimization flags to
the list?  There is definitely a problem with JacobiN that needs to be
fixed.  The fix should be very easy to do if we can get a matrix that
reliably causes JacobiN to fail when certain optimization flags are
used, so if either of you can print out such a matrix (with all
numbers printed with a precision of 20 digits), it would be a big
help.

 - David


2012/1/31 Dženan Zukić <dzenanz at gmail.com>:
> I also saw this warning recently, from the block that "never gets called".
> And it only happened in release version of my program.
>
> On Tue, Jan 31, 2012 at 00:48, Maarten Beek <beekmaarten at yahoo.com> wrote:
>>
>> Hi David,
>>
>> Ai, seems these crashes are hard to get rid off....
>>
>> I currently use VTK within Amira modules.
>>
>> I changed the type of vtkPoints from the default VTK_FLOAT to VTK_DOUBLE
>> when I convert an Amira object to a VTK object. This reduces the occurrences
>> of the errors, but doesn't solve the issue.
>> (Ps: why is the default in vtkPoints still float, while everywhere else
>> floats were changed into doubles a long while ago?)
>>
>> I don't really know much about different optimizations, so I just
>> copy-paste what I found in MSVS:
>>
>> I build my VTK with:
>> /O2 /Ob2 /FD /EHsc /MD /Fo"vtkCommon.dir\Release\\"
>> /Fd"G:\vtk-5.6.0\build_vs90_noQt\bin\Release/vtkCommon.pdb" /W4 /nologo /c
>> /TP /errorReport:prompt/Zm 1000 and a couple of '/I'-s and '/D'-s
>>
>> I build my Amira modules with:
>> /O2 /Ob1 /Oi /Oy /GF /FD /EHsc /MD /GS- /Gy /fp:fast /openmp
>> /Fo"./../../obj/arch-Win64VC9-Optimize/GraphPackage/"
>> /Fd"./../.././bin/arch-Win64VC9-Optimize/GraphPackage.pdb" /W3 /nologo /c
>> /Zi /wd4068 /wd4305 /wd4018 /wd4244 /wd4800 /wd4275 /wd4251
>> /errorReport:prompt and a couple of '/I'-s and '/D'-s
>>
>> I am working on getting vtkMath::JacobiN to print the matrix in the
>> if-loop that 'gets never called' using vtkGenericWarningMacro to avoid
>> having to include Amira stuff. Having a hard time getting that to work. (
>> char* test = "hello";vtkGenericWarningMacro( test ); won't do the trick).
>> Any suggestions?
>>
>> Maarten
>>
>> ________________________________
>> From: David Gobbi <david.gobbi at gmail.com>
>> To: Maarten Beek <beekmaarten at yahoo.com>
>> Cc: VTK list <vtkusers at vtk.org>
>> Sent: Monday, January 30, 2012 2:31:38 PM
>> Subject: Re: [vtkusers] ICP Error: vtkMath::Jacobi: Error extracting
>> eigenfunctions
>>
>> Hi Maarten,
>>
>> I think there are two issues here, one is that vtkLandmarkTransform
>> should have a check as you have described, but another potentially
>> serious issue is that, as far as I understand it, JacobiN should never
>> fail.  I did a google search and found a message from 2002 by the
>> Numerical Recipes authors stating that the NR Jacobi code can become
>> numerically unstable due to certain compiler optimizations.  I'm
>> guessing that certain compiler optimizations could similarly make the
>> VTK Jacobi code become unstable.
>> http://www.nr.com/forum/showthread.php?p=4913
>>
>> Can you provide info about your compiler/flags etc?  Also, is it
>> possible to get your code to print a matrix that causes JacobiN to
>> fail?
>>
>> - David
>>
>>
>> On Mon, Jan 30, 2012 at 9:44 AM, Maarten Beek <beekmaarten at yahoo.com>
>> wrote:
>> > Hi all,
>> >
>> > I get the following warning when using ICP:
>> >
>> > vtkMath::Jacobi: Error extracting eigenfunctions
>> >
>> > It comes from vtkMath::vtkJacobiN that calculates the eigenvalues,
>> > -vectors
>> > of a matrix.
>> > The function returns 0, when this error occurs (otherwise 1), but
>> > vtkLandmarkTransform doesn't check for the return value and thus uses
>> > undefined values for the eigenvalues, -vectors.
>> > This means my point set becomes invalid.
>> > I believe the way to avoid this error is to 'giggle' the coordinates a
>> > little when it happens, but how can I intervene when
>> > vtkLandmarkTransform
>> > stubbornly uses whatever values it gets from vtkMath::vtkJacobiN?
>> > Is there a way to intercept the error message?
>> >
>> > I also noticed that if I apply ICP on A and B1 resulting in the error
>> > message, applying ICP on A and B2 (loading the same data file that gives
>> > me
>> > B1) works fine. I don't see vtkMath::vtkJacobiN using a random number or
>> > doing something similar, which makes me believe the error message I get
>> > is
>> > due to floating point accuracy? Even more a reason to think that
>> > 'giggling'
>> > might work (if I were able to intervene before the invalid transform is
>> > applied to my data...)
>> >
>> > Thanks - Maarten