[Insight-developers] 0008911: Numerical issues in vnl matrix inversion?

[Bill Lorensen]

With your patch, the test passes. However, if I use the original
itkMatrix.h code but change the matlab-related matrices to double, the
test also passes. Looking at the matlab matrix, I think computing the
inverse in double makes sense. Perhaps we should leave itkMatrix alone
and fix the test to use double?

Bill


On Mon, Jul 27, 2009 at 12:00 PM, Bill Lorensen<bill.lorensen at gmail.com> wrote:
> I'll try it on my gcc4.3 system.
>
> On Mon, Jul 27, 2009 at 11:50 AM, Tom
> Vercauteren<tom.vercauteren at m4x.org> wrote:
>> Hi Bill,
>>
>> I was actually writing an email about that exact matter :)
>>
>> A few days ago, I tried to replicate bug 8911
>> http://www.itk.org/Bug/view.php?id=8911
>>
>> I couldn't do it on my machine but since I had the test written, I
>> decided to commit it. Now I see it failing on a few machines. So
>> apparently, bug 8911 can be replicated.
>>
>> I agree that letting vxl folks fix it would be good. Another option
>> would be to try a fix on ITK's side (which would be faster). I already
>> prepared something but cannot currently test whether it works or not.
>> The tentative patch is attached here and to the bug tracker. Could you
>> try it on your system?
>>
>> Thanks,
>> Tom
>>
>> On Mon, Jul 27, 2009 at 17:40, Bill Lorensen<bill.lorensen at gmail.com> wrote:
>>> Tom,
>>>
>>> I see that you checked in a test that exhibits the failing inversion.
>>> It fails on Borland, gcc 4.3 and MAC 4.0. Does it pass on your system?
>>>
>>> Is there a plan to fix this? Perhaps we should we let the vxl folks fix it?
>>>
>>> Bill
>>>
>>
>