[ITK] [ITK-dev] expectationmaximizationMixtureModelEstimator bug

[Matt McCormick]

Hi Wei,

Great job locating the issue!

Could the example be place in a test for the
ExpectionMaximizationMixtureModelEstimator and the fix be place in a
patch so that you get proper credit for your work [1]?  Please let us
know if you have any questions.

Thanks,
Matt

[1] http://insightsoftwareconsortium.github.io/ITKBarCamp-doc/CommunitySoftwareProcess/SubmitAPatchToGerrit/index.html

On Tue, Mar 18, 2014 at 2:03 PM, Wei Liu <weiliu620 at gmail.com> wrote:
> Dear ITK developers,
>
> I've found that the filter does not work even on the example code [1]. In
> this example, there are two Gaussian components defined, but the parameters
> of the second component is never updated. The reason is in the
> iktExpectationMaximizationMixtureModelEstimator.hxx, the
> UpdateComponentParameters function stops early. Here is the code that need
> to be changted.
>
> _______________________________
> template< typename TSample >
> bool
> ExpectationMaximizationMixtureModelEstimator< TSample >
> ::UpdateComponentParameters()
> {
>   bool           updated = false;
>   ComponentType *component;
>
>   for ( size_t componentIndex = 0; componentIndex <
> m_ComponentVector.size();
>         ++componentIndex )
>     {
>     component = m_ComponentVector[componentIndex];
>     component->Update();
>     if ( component->AreParametersModified() )
>       {
>       // return true;
>   updated = true;
>       }
>     }
>
>   return updated;
> }
>
> _____________________________________________
>
> We need to change the variable 'updated' instead of 'return true',
> otherwise, the remaining components can not get the parameters updated.
> After fixed, the example program works.
>
>
> [1]
> http://www.itk.org/Wiki/ITK/Examples/Statistics/ExpectationMaximizationMixtureModelEstimator_2D
>
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