[jira] Closed: (MATH-297) Eigenvector computation incorrectly returning vectors of NaNs

["Phil Steitz (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/MATH-297?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Phil Steitz closed MATH-297.
----------------------------


> Eigenvector computation incorrectly returning vectors of NaNs
> -------------------------------------------------------------
>
>                 Key: MATH-297
>                 URL: https://issues.apache.org/jira/browse/MATH-297
>             Project: Commons Math
>          Issue Type: Bug
>    Affects Versions: 2.0
>            Reporter: Phil Steitz
>             Fix For: 2.1
>
>
> As reported by Axel Kramer on commons-dev, the following test case succeeds, but should fail:
> {code}
> public void testEigenDecomposition() {
>     double[][] m = { { 0.0, 1.0, -1.0 }, { 1.0, 1.0, 0.0 }, { -1.0,0.0, 1.0 } };
>     RealMatrix rm = new Array2DRowRealMatrix(m);
>     assertEquals(rm.toString(),
>         "Array2DRowRealMatrix{{0.0,1.0,-1.0},{1.0,1.0,0.0},{-1.0,0.0,1.0}}");
>     EigenDecompositionImpl ed = new EigenDecompositionImpl(rm,
>         MathUtils.SAFE_MIN);
>     RealVector rv0 = ed.getEigenvector(0);
>     assertEquals(rv0.toString(), "{(NaN); (NaN); (NaN)}");
>   }
> {code}
> ed.getRealEigenvalues() returns the correct eigenvalues (2, 1, -1), but all three eigenvectors contain only NaNs.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: https://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira