#7325: Sage cannot solve inequalities
-----------------------------------+----------------------------------------
Reporter: robert.marik | Owner: tbd
Type: enhancement | Status: positive_review
Priority: major | Milestone: sage-4.3.2
Component: algebra | Keywords: relation, symbolics,
inequality, solve
Author: Robert Marik | Upstream: N/A
Reviewer: Karl-Dieter Crisman | Merged:
Work_issues: |
-----------------------------------+----------------------------------------
Comment(by kcrisman):
Replying to [comment:34 robert.marik]:
> Replying to [comment:32 kcrisman]:
> > There were some additional examples which still were platform-
dependent. This is really weird, I have to say! In particular, the
following
> > {{{
> > try:
> > return(solve_ineq(self)) # trying
solve_ineq_univar
> > except:
> > pass
> > try:
> > return(solve_ineq([self])) # trying
solve_ineq_fourier
> > }}}
> > means that exp.solve(x) ignores the x. However, I don't know that
that is really worth changing since it still gives correct answers.
>
> Perhaps to explain in more details what happens for ineq.solve(x):
>
> * ineq has not equality sign, the previous version of solve command
raised error, the new version excutes the code above
Oh, yes, I understand, I am just suggesting that in the future solve
itself (not just solve_ineq) could take the variable given into account as
well.
>
> * we try solve_ineq(self), i.e. we use the Maxima's solve_rat_ineq. This
raises error if there are more than one variable and if the solve_rat_ineq
is not polynomial or quotient of two polynomial (after moving right hand
side to the left and simplifying). Hence this function does not need the
name of the variable on input. this is because solve_rat_ineq handles
rational inequalities better than fourier_elim
>
Yes, of course. Again, just suggesting that in the future (because the
variable order matters for some reason) that the variables could fit in
here in the future. It's still great work!
Incidentally, on Linux:
{{{
sage: set((x,y))
set([y, x])
}}}
On Mac:
{{{
sage: set((x,y))
set([x, y])
}}}
So that is why we are seeing these changes. Probably something other than
set could solve this issue, so I may open a new ticket for that.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/7325#comment:35>
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 post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
