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https://issues.apache.org/jira/browse/MATH-274?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Luc Maisonobe closed MATH-274.
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closing resolved issue for 2.0 release

> testing for symmetric positive definite matrix in CholeskyDecomposition
> -----------------------------------------------------------------------
>
>                 Key: MATH-274
>                 URL: https://issues.apache.org/jira/browse/MATH-274
>             Project: Commons Math
>          Issue Type: Bug
>    Affects Versions: 2.0
>         Environment: Mac OS X, NetBeans
>            Reporter: Manuel Rossetti
>            Assignee: Luc Maisonobe
>            Priority: Minor
>             Fix For: 2.0
>
>
> I used this matrix:
>         double[][] cv = {
>             {0.40434286, 0.09376327, 0.30328980, 0.04909388},
>             {0.09376327, 0.10400408, 0.07137959, 0.04762857},
>             {0.30328980, 0.07137959, 0.30458776, 0.04882449},
>             {0.04909388, 0.04762857, 0.04882449, 0.07543265}
>         };
> And it works fine, because it is symmetric positive definite
> I tried this matrix:
>         double[][] cv = {
>             {0.40434286, -0.09376327, 0.30328980, 0.04909388},
>             {-0.09376327, 0.10400408, 0.07137959, 0.04762857},
>             {0.30328980, 0.07137959, 0.30458776, 0.04882449},
>             {0.04909388, 0.04762857, 0.04882449, 0.07543265}
>         };
> And it should throw an exception but it does not.  I tested the matrix in R 
> and R's cholesky decomposition method returns that the matrix is not 
> symmetric positive definite.
> Obviously your code is not catching this appropriately.
> By the way (in my opinion) the use of exceptions to check these conditions is 
> not the best design or use for exceptions.  If you are going to force the use 
> to try and catch these exceptions at least provide methods  to test the 
> conditions prior to the possibility of the exception.  

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