Mercurial > jwe > octave
changeset 26734:75d79c39ac92
Replace '-0' in sigma matrix from svd() with '+0' (bug #55710).
* liboctave/numeric/svd.cc (svd (const T& a, svd::Type type, svd::Driver
driver): After calling LAPACK routine to calculate svd, check for zeros
in sigma matrix and replace them with '+0'.
* libinterp/corefcn/svd.cc (Fsvd): Add BIST test for bug #55710.
| author | Rik <rik@octave.org> |
|---|---|
| date | Thu, 14 Feb 2019 16:38:00 -0800 |
| parents | f034b29320ad |
| children | f85d491d2322 |
| files | libinterp/corefcn/svd.cc liboctave/numeric/svd.cc |
| diffstat | 2 files changed, 9 insertions(+), 0 deletions(-) [+] |
line wrap: on
line diff
--- a/libinterp/corefcn/svd.cc Fri Feb 08 18:07:33 2019 +0100 +++ b/libinterp/corefcn/svd.cc Thu Feb 14 16:38:00 2019 -0800 @@ -372,6 +372,8 @@ %! [~,~,v] = svd ([1, 1, 1], "econ"); %! assert (size (v), [3 1]); +%!assert <*55710> (1 / svd (-0), Inf) + %!error svd () %!error svd ([1, 2; 4, 5], 2, 3) */
--- a/liboctave/numeric/svd.cc Fri Feb 08 18:07:33 2019 +0100 +++ b/liboctave/numeric/svd.cc Thu Feb 14 16:38:00 2019 -0800 @@ -385,6 +385,13 @@ else (*current_liboctave_error_handler) ("svd: unknown driver"); + // LAPACK can return -0 which is a small problem (bug #55710). + for (octave_idx_type i = 0; i < sigma.diag_length (); i++) + { + if (! sigma.dgxelem (i)) + sigma.dgxelem (i) = DM_P (0); + } + if (! (jobv == 'N' || jobv == 'O')) right_sm = right_sm.hermitian (); }