Opened 11 years ago
Closed 7 months ago
#9825 closed defect (fixed)
desolve_system unable to interpret ilt and Maxima's temporary variables
Reported by: | rhinton | Owned by: | burcin |
---|---|---|---|
Priority: | major | Milestone: | sage-9.3 |
Component: | calculus | Keywords: | calculus, maxima, symbolics |
Cc: | robert.marik | Merged in: | |
Authors: | Emmanuel Charpentier | Reviewers: | Karl-Dieter Crisman |
Report Upstream: | Fixed upstream, in a later stable release. | Work issues: | |
Branch: | 74d88f4 (Commits, GitHub, GitLab) | Commit: | 74d88f4c23873e83dad685dc1dbc4530f38bfb52 |
Dependencies: | Stopgaps: |
Description
desolve_system sometimes generates a Maxima result that includes temporary variables that Sage does not parse correctly.
sage: t = var('t') sage: x1 = function('x1', t) sage: x2 = function('x2', t) sage: de1 = (diff(x1,t) == -3*(x2^2-1)) sage: de2 = (diff(x2,t) == 1) sage: desolve_system([de1, de2], [x1, x2], ivar=t) ... TypeError: unable to make sense of Maxima expression 'x1(t)=ilt(-((3*laplace(x2(t)^2,t,?g1543)-x1(0))*?g1543-3)/?g1543^2,?g1543,t)' in Sage
Change History (22)
comment:1 follow-up: ↓ 2 Changed 11 years ago by
comment:2 in reply to: ↑ 1 Changed 11 years ago by
Replying to kcrisman:
On [ this Maxima list thread] we get the original system in Maxima notation - thanks to Stavros Macrackis:
Meaning this thread.
comment:3 Changed 9 years ago by
I've followed up again at this new thread - apparently it never actually made it to their bug tracker?
comment:4 Changed 9 years ago by
See also this ask.sagemath question.
comment:5 Changed 8 years ago by
And this ask.sagemath question, thought here Maxima is actually asking a question about these variables!
comment:6 Changed 8 years ago by
- Milestone changed from sage-5.11 to sage-5.12
comment:7 Changed 8 years ago by
- Milestone changed from sage-6.1 to sage-6.2
comment:8 Changed 7 years ago by
- Milestone changed from sage-6.2 to sage-6.3
comment:9 Changed 7 years ago by
- Report Upstream changed from N/A to Reported upstream. No feedback yet.
comment:10 Changed 7 years ago by
Did you report it upstream to their bug tracker? I never heard on either of these emails, so I think this is how it will have to be reported.
comment:11 Changed 7 years ago by
I took your repeated mail to the list as report.
comment:12 Changed 7 years ago by
Sadly, that isn't always enough :( Reported upstream here, however, just now. There was internal discussion in the original Maxima thread so I took it that the experts had several possible resolutions.
comment:13 Changed 7 years ago by
- Milestone changed from sage-6.3 to sage-6.4
comment:14 Changed 7 years ago by
- Report Upstream changed from Reported upstream. No feedback yet. to Fixed upstream, in a later stable release.
Upstream seems to have made a change that would do something about this. Anyone want to give it a whirl?
comment:15 follow-up: ↓ 16 Changed 7 years ago by
- Summary changed from desolve_system unable to interpret Maxima's temporary variables to desolve_system unable to interpret ilt and Maxima's temporary variables
This now returns [x1(t) == ilt(-(3*g3390*laplace(x2(t)^2, t, g3390) - g3390*x1(0) - 3)/g3390^2, g3390, t), x2(t) == t + x2(0)]
so it becomes an issue to fix our Maxima interface.
comment:16 in reply to: ↑ 15 Changed 7 years ago by
Replying to rws:
This now returns
[x1(t) == ilt(-(3*g3390*laplace(x2(t)^2, t, g3390) - g3390*x1(0) - 3)/g3390^2, g3390, t), x2(t) == t + x2(0)]
so it becomes an issue to fix our Maxima interface.
According to the documentation of inverse_laplace
this is probably more or less correct. We might want to do something about "ilt" so that it is more closely tied to inverse_laplace
, though.
comment:17 Changed 7 months ago by
- Milestone changed from sage-6.4 to sage-duplicate/invalid/wontfix
- Status changed from new to needs_review
This is now fixed (probably due to upstream upgrade) :
sage: x1, x2=function("x1, x2") sage: de1=x1(t).diff(t)==-3*(x2(t)-1) sage: de2=x2(t).diff(t)==1 sage: Sol=desolve_system([de1, de2],[x1(t),x2(t)],ivar=t) ; Sol [x1(t) == -3/2*t^2 - 3*t*x2(0) + 3*t + x1(0), x2(t) == t + x2(0)]
==> invalidation of the bug and review query in order to get this bug closed.
HTH,
comment:18 Changed 7 months ago by
- Status changed from needs_review to needs_work
I guess as usual doctest needed? Looks like it was a combination of their upstream fix and something we did to parse it right.
comment:19 Changed 7 months ago by
- Branch set to u/charpent/desolve_system_unable_to_interpret_ilt_and_maxima_s_temporary_variables
comment:20 Changed 7 months ago by
- Commit set to 74d88f4c23873e83dad685dc1dbc4530f38bfb52
- Milestone changed from sage-duplicate/invalid/wontfix to sage-9.3
- Status changed from needs_work to needs_review
comment:21 Changed 7 months ago by
- Reviewers set to Karl-Dieter Crisman
- Status changed from needs_review to positive_review
Thanks, this is great. Despite patchbot not yet reporting and my own Sage install being too brittle to test, Cell server says it's fine so let's do it.
comment:22 Changed 7 months ago by
- Branch changed from u/charpent/desolve_system_unable_to_interpret_ilt_and_maxima_s_temporary_variables to 74d88f4c23873e83dad685dc1dbc4530f38bfb52
- Resolution set to fixed
- Status changed from positive_review to closed
On [ this Maxima list thread] we get the original system in Maxima notation - thanks to Stavros Macrackis:
He also provides a simpler example which does this:
The suggestion is that the ilt should be replacing the
?g1234
type variables (which are indeed dummy variables, but native Lisp ones) by Maxima-type ones, so I am putting to reported upstream, developers acknowledge bug. However, my feeling is that we should fix this by parsing these things as well, should they come up again.