#14965: FloatingPoint exception when multiplying matrix over QQ by vector over
SR
-------------------------------------+-------------------------------------
Reporter: dkrenn | Owner:
Type: defect | Status: needs_info
Priority: major | Milestone: sage-
Component: linear algebra | duplicate/invalid/wontfix
Keywords: matrix, vector, | Resolution:
mutliplication, floatingpoint | Merged in:
exception | Reviewers: Jeroen Demeyer
Authors: | Work issues:
Report Upstream: N/A | Commit:
Branch: | Stopgaps:
Dependencies: |
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Changes (by nbruin):
* status: positive_review => needs_info
Comment:
but not for me. The error I get is coming from the following maxima
statement, which seems to reliably fail in 5.29.1 and 50.30.0 (shipped
with fedora, running on SBCL):
{{{
(%i1) is
(notequal(84644440725961403098463183554485799389772425728699536724546678651368471662755793858191462623325951275455550962101277270763335324980423888503086416881487600951168887632284102290001262851926718316596582705934285641705714110547524777517804311041930987129930496818273454551255885915706318740821679919000000000000000000000*x/422165920314471048721358275854632323285179941428330150821135511815100042994592631347355397175387243022779234708963662480477375868719044084318634583443223137428890926160543699705457864438134730545535596936604372279922247951010042249163649352110753480952771747316504857000652757440826179465253453626540111934123296968384641+2097152/10460353203,0));
Maxima encountered a Lisp error:
#<a ARITHMETIC-ERROR>
}}}
On SBCL the error message given is a bit more informative:
{{{
Maxima encountered a Lisp error:
Too large to be represented as a DOUBLE-FLOAT:
40361614573460294293624488618128680891882145752286690103791560483631358939531227997871142684615111959197783928919447551137607252588474220515769203606361198878845638099805880684853202272380217703150073388068335362294060759805452717551138072510686391415562866601120688701274817426541480417643394431591033935546875
}}}
which is probably correct. It may well be that a very new sage version
avoids this code path, but 6.3b1 still has the problem. I'm for now
reverting the status of the ticket to a more open one. Once we can confirm
the problem is really gone and it's not just Jeroen's magic FPU, we can
close this ticket.
Even if sage doesn't trigger this error anymore, it definitely seems an
error upstream, so we may want to test and report if this problem hasn't
been addressed in maxima's latest release.
--
Ticket URL: <http://trac.sagemath.org/ticket/14965#comment:3>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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