#16643: integrate() problem
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Reporter: rws | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.3
Component: symbolics | Resolution:
Keywords: integration, maxima | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: | Stopgaps:
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Description changed by nbruin:
Old description:
> I interrupted Sage after 5min of churning without result:
> {{{
> sage: f=diff((tan(x)+x)*e^tan(x),x)
> (tan(x)^2 + 1)*(x + tan(x))*e^tan(x) + (tan(x)^2 + 2)*e^tan(x)
> sage: integrate(f,x)
> }}}
> On a faster computer:
> {{{
> sage: %time integrate(f,x)
> CPU times: user 3min 58s, sys: 50 ms, total: 3min 58s
> Wall time: 3min 58s
> integrate((tan(x)^2 + 1)*(x + tan(x))*e^tan(x) + (tan(x)^2 + 2)*e^tan(x),
> x)
> }}}
> On the other hand, for the equivalent expression
> {{{
> sage: g=e^tan(x)*sec(x)^2*(tan(x)+x)+e^tan(x)*(sec(x)^2+1)
> sageRuntimeError: ECL says: In function CAR, the value of the first
> argument is
> 0
> which is not of the expected type LIST: %time integrate(g,x)
> }}}
> which happens in maxima/ECL with `abs_integrate` loaded, but not in
> maxima/SBCL. Upstream: [https://sourceforge.net/p/maxima/bugs/2781/]
New description:
I interrupted Sage after 5min of churning without result:
{{{
sage: f=diff((tan(x)+x)*e^tan(x),x)
(tan(x)^2 + 1)*(x + tan(x))*e^tan(x) + (tan(x)^2 + 2)*e^tan(x)
sage: integrate(f,x)
}}}
On a faster computer:
{{{
sage: %time integrate(f,x)
CPU times: user 3min 58s, sys: 50 ms, total: 3min 58s
Wall time: 3min 58s
integrate((tan(x)^2 + 1)*(x + tan(x))*e^tan(x) + (tan(x)^2 + 2)*e^tan(x),
x)
}}}
On the other hand, for the equivalent expression
{{{
sage: g=e^tan(x)*sec(x)^2*(tan(x)+x)+e^tan(x)*(sec(x)^2+1)
sage: %time integrate(g,x)
RuntimeError: ECL says: In function CAR, the value of the first argument
is
0
which is not of the expected type LIST
}}}
which happens in maxima/ECL with `abs_integrate` loaded, but not in
maxima/SBCL. Upstream: [https://sourceforge.net/p/maxima/bugs/2781/]
--
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Ticket URL: <http://trac.sagemath.org/ticket/16643#comment:5>
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