#10682: sum fails with lower bound != 0 or 1 (upgrade maxima to 5.26)
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Reporter: fmaltey
| Owner: burcin
Type: defect
| Status: needs_work
Priority: critical
| Milestone: sage-5.0
Component: symbolics
| Keywords:
Work_issues: several doctests need to be patched due to changes in output
format/term order | Upstream: N/A
Reviewer:
| Author:
Merged:
| Dependencies:
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Comment(by nbruin):
Thanks for preparing the spkg, Dima! My problem was probably that I didn't
rebuild ecl first. It works very well now. I think I found the culprit for
the desolve problem:
{{{
Maxima 5.26.0 http://maxima.sourceforge.net
using Lisp ECL 11.1.1
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) display2d: false;
(%o1) false
(%i2) load('contrib_ode);
(%o2)
"/mnt/usb1/scratch/nbruin/5.0/local/share/maxima/5.26.0/share/contrib/diffequations/contrib_ode.mac"
(%i3) domain : complex;
(%o3) complex
(%i4) assume(x>0);
(%o4) [x > 0]
(%i5) assume(y>0);
(%o5) [y > 0]
(%i6) contrib_ode(x*'diff(y,x,1)-x*sqrt(y^2+x^2)-y,y,x);
(%o6)
[(log((2*sqrt(4/x^2)*x^2*sqrt((4*y^4+4*x^2*y^2)/x^2)+8*y^2+4*x^2)/x^2)
-sqrt(4/x^2)*x*asinh(2*y^2/(x*sqrt(4*y^2)))
-sqrt(4/x^2)*x*asinh(2*y/sqrt(4*x^2))+sqrt(4/x^2)*x^2)
/(sqrt(4/x^2)*x)
= %c]
(%i7) domain: real;
(%o7) real
(%i8) contrib_ode(x*'diff(y,x,1)-x*sqrt(y^2+x^2)-y,y,x);
(%o8) [x-asinh(y/x) = %c]
}}}
so the problem is that we set "domain: complex" and apparently the
behaviour of something there has changed. The assumptions x>0 and y>0
imply that x,y are real (and maxima's assume facility agrees with that),
but as we are well aware, assumptions don't get used everywhere. At the
very least, it seems that assumptions on variables do not affect all the
things that "domain: complex" affects.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/10682#comment:16>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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