View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001373 | OpenFOAM | Bug | public | 2014-08-14 14:38 | 2014-08-28 11:30 |
| Reporter | Assigned To | will | |||
| Priority | normal | Severity | major | Reproducibility | always |
| Status | resolved | Resolution | fixed | ||
| Platform | Linux | OS | Other | OS Version | (please specify) |
| Summary | 0001373: Bug in eigen vector computation of tensor (2.3.0) | ||||
| Description | 1) the eigenvector computation returns zero vectors in case of multiple eigenvalues 2) Another problem seems to exist with the sensitivy of the symmetry check. It occurs quite often, that matrices which are supposed to be symmetric, but are slightly off due to numerical errors produce zero vectors: This is not covered by the attached test, but seems to originate from /src/OpenFOAM/primitives/Tensor/tensor/tensor.C:179 | ||||
| Steps To Reproduce | modified tensor test shows the problem. see attached file which creates the following output: tensor 1: (0.333 0 0 0 0.333 0 0 0 0.333) tensor 2: (0.333 0 0 0 0.333 0 0 0 0.335) tensor 3: (0.333 0 0 0 0.334 0 0 0 0.335) eigenvalues 1: (0.333 0.333 0.333) eigenvalues 2: (0.333 0.333 0.335) eigenvalues 3: (0.333 0.334 0.335) eigenvectors 1: (0 0 0 0 0 0 0 0 0) eigenvectors 2: (0 0 0 0 0 0 0 0 1) eigenvectors 3: (1 0 0 -0 1 -0 0 0 1) | ||||
| Tags | No tags attached. | ||||
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2014-08-14 14:38
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Thanks for the report. This has been fixed in commits 50b81a7 and 68fcd7a so that repeated roots of the characteristic polynomial are now handled. Your tensors, as well as a number of other awkward ones, are now computed correctly. It's a significant rewrite, though, so there may be some bugs. Please report back if you have any issues. |
