#14403: Symbolic charpoly broken
-------------------------+--------------------------------------------------
Reporter: nbruin | Owner: burcin
Type: defect | Status: new
Priority: major | Milestone: sage-5.9
Component: symbolics | Keywords:
Work issues: | Report Upstream: N/A
Reviewers: | Authors:
Merged in: | Dependencies:
Stopgaps: |
-------------------------+--------------------------------------------------
see [https://groups.google.com/group/sage-
devel/browse_thread/thread/71d76cd072fe17eb?hl=en sage-devel].
Not good:
{{{
sage: a=matrix([[x,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]])
sage: charpoly(a)
0
}}}
Also not good
{{{
sage: var('y')
sage: b=matrix([[y^(1/2),0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]])
sage: charpoly(b)
Error
}}}
Both can be solved by doing something more along the lines of
{{{
V=SR('crazy_varname')
cp=self._maxima_(maxima).charpoly('crazy_varname')._sage_().expand()
SR[var](list(cp.coefficient(V,i) for i in range(self.nrows()+1)))
}}}
in `a.charpoly`.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/14403>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.
