#13052: Positive definte check for matrices over RDF/CDF
----------------------------------+-----------------------------------------
Reporter: rbeezer | Owner: jason, was
Type: enhancement | Status: needs_review
Priority: minor | Milestone: sage-5.1
Component: linear algebra | Resolution:
Keywords: sd40.5 | Work issues:
Report Upstream: N/A | Reviewers:
Authors: Rob Beezer | Merged in:
Dependencies: #13035 | Stopgaps:
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Comment (by ddrake):
''Without'' the referee patch from #13035 (which does not affect
functionality), I get some numerical noise on 64-bit Ubuntu 10.04:
{{{
sage -t devel/sage/sage/matrix/matrix_double_dense.pyx
**********************************************************************
File "/home/drake/s/sage-5.1.beta0/devel/sage-
main/sage/matrix/matrix_double_dense.pyx", line 3537:
sage: [M[:i,:i].determinant() for i in range(1, M.nrows()+1)]
Expected:
[1.0, 4.0, 460.0, 27936.0, 82944.0]
Got:
[1.0, 4.0, 460.0, 27936.0, 82943.9999998]
**********************************************************************
}}}
That's from an integer matrix, so putting a `round()` in there will not
harm anything.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/13052#comment:5>
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