Opened 2 years ago
Last modified 5 weeks ago
#26563 needs_review defect
Sage screws up the integration of some functions.
Reported by:  charpent  Owned by:  

Priority:  major  Milestone:  sage8.5 
Component:  symbolics  Keywords:  integration, abs_integrate 
Cc:  mforets, chapoton  Merged in:  
Authors:  Michael Orlitzky  Reviewers:  
Report Upstream:  N/A  Work issues:  
Branch:  u/mjo/ticket/26563 (Commits)  Commit:  117fb428cb898d479383a381fff302ba4848a43f 
Dependencies:  Stopgaps: 
Description (last modified by )
Inspiration this ask.sagemath question.Edit: this one seems to be another instance of the same problem.
A lot of tickets describe indefinite integral bugs attributable to maxima
, most notably its abs_integrate
package ; see #12731 for a sample of the latter, and the list of integration tickets for somother infamous examples...
However, Sage, which is becoming a mature system, seems to have become able to screw up things by itself on its own, without any external help. Case in point :
sage: elliptic_e(x,1/2).diff(x) sqrt(1/2*sin(x)^2 + 1)
 Maxima can't solve the reverse problem, but will honestly report its failure :
sage: maxima.integrate(sqrt(1m*sin(x)^2),x).sage() integrate(sqrt(m*sin(x)^2 + 1), x)
 Sage will lie ;) :
sage: integrate(sqrt(1m*sin(x)^2),x) 1/4*m*x  1/8*m*sin(2*x)
which is wrong, wrong, wrong...
Change History (6)
comment:1 Changed 2 years ago by
comment:2 Changed 2 years ago by
 Cc mforets added
comment:3 Changed 2 years ago by
 Description modified (diff)
comment:4 Changed 20 months ago by
 Keywords abs_integrate added
comment:5 Changed 19 months ago by
fixed by #27958, that needs review
comment:6 Changed 5 weeks ago by
 Branch set to u/mjo/ticket/26563
 Cc chapoton added
 Commit set to 117fb428cb898d479383a381fff302ba4848a43f
 Status changed from new to needs_review
New commits:
117fb42  Trac #26563: check the fundamental theorem of calculus for elliptic_e().

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I think that this actually is due to
abs_integrate
:(although it's quite interesting what sage does with the result...)