id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
6816 [with patch, needs review] sage/maxima hang when doing an indefinite integral was burcin "Integration sometimes hangs in sage-4.1.1.
{{{
flat:~ wstein$ sage
----------------------------------------------------------------------
| Sage Version 4.1.1, Release Date: 2009-08-14 |
| Type notebook() for the GUI, and license() for information. |
----------------------------------------------------------------------
sage: var('t,theta')
(t, theta)
sage: integrate(t * cos(-theta*t), (t,-oo,oo))
[.. and it hangs forever ..]
}}}
In fact, in Maxima what is happening is the following:
{{{
(%i6) integrate(t*cos(-theta*t),t,-inf,inf);
Is theta positive, negative, or zero?
positive <--- i type this.
;
(%o6) 0
(%i7)
}}}
For some reason the question ""Is theta positive, negative, or zero?"" is not getting seen by pexpect as it should. Argh!
This works in Maxima:
{{{
(%i1) assume(theta>0);
(%o1) [theta > 0]
(%i2) integrate(t*cos(-theta*t),t,-inf,inf);
(%o2) 0
}}}
The same doesn't work in Sage though, which is very weird:
{{{
sage: var('t,theta')
(t, theta)
sage: assume(theta>0)
sage: integrate(t * cos(-theta*t), (t,-oo,oo))
}}}" defect closed major sage-duplicate/invalid/wontfix calculus duplicate mhansen Karl-Dieter Crisman N/A