[Insight-developers] DeformableRegistration6 Example failing : min() and Schizophrenia

[Luis Ibanez]

This seems to be because VXL defined "min()" in this
'particular' way in vcl_numeric_limits and ITK inherited
this definition in the NumericTraits ?

It seems that they used "min()" when they meant the
"SmallestPositive()" number.


E.g. for float, they use

       min() == 1.175 e-38.

and for double they use

       min() == 2.22 e-308



Nothing prevent us from skipping the vcl definition,
and doing the right thing in itkNumericTraits...


   Luis



--------------------------------
Miller, James V (Research) wrote:

> The problem is min() on signed integral types is the negative value in
> dynamic range, min() on unsigned integral types is zero (still the 
> minimum of the dynamic range) BUT min() ON FLOATING POINT NUMBERS IS THE
> "Minimum positive normalized value"!!!
> 
> UGGH
> 
> 
> -----Original Message-----
> From: Luis Ibanez [mailto:luis.ibanez at kitware.com]
> Sent: Friday, October 08, 2004 10:03 AM
> To: Lorensen, William E (Research)
> Cc: Insight-developers (E-mail)
> Subject: Re: [Insight-developers] DeformableRegistration6 Example
> failing
> 
> 
> 
> Bill,
> 
> Thanks for tracking it down.
> 
> I was naively assuming that min() was returning
> the actual negative value.
> 
> maybe we should rename "min()" as "PositiveMin()"
> so we have
> 
> 
>         PositiveMin();       and
>         NonpositiveMin();
> 
> 
> 
>     Luis
> 
> 
> --------------------------------------
> Lorensen, William E (Research) wrote:
> 
> 
>>Found it! You where using min() instead of NonpositiveMin(). I'll check it
>>in oncc I run the tests.
>>
>>Bill
>>
>>-----Original Message-----
>>From: Lorensen, William E (Research) [mailto:lorensen at crd.ge.com]
>>Sent: Thursday, October 07, 2004 3:05 PM
>>To: 'Luis Ibanez'
>>Cc: Insight-developers (E-mail)
>>Subject: [Insight-developers] DeformableRegistration6 Example failing
>>
>>
>>Luis,
>>The subject example has been failing for agout 9 days. This coincides with
>>your changes to the BSplineDeformableTransform. However, I can't see how
>>your changes could affect the results. I checked out the prior version and
>>got the same bad results.
>>
>>Then I checkedout a prior verion of itkResampleImageFilter.txx and
> 
> rebuilt,
> 
>>I get the good old answers. I think the clamping logic is flawed. I'll
> 
> track
> 
>>it down unless you would rather do it.
>>
>>Bill
>>
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>>
> 
> 
> 
> 
> 
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