Interface problem, integrate with giac

asked 2018-06-21 12:50:03 +0100

Nasser gravatar image

updated 2018-06-21 13:23:26 +0100

Is this a known issue? Using sage 8.3 beta 6.

I reported this at https://trac.sagemath.org/ticket/25626 

sage: var('t')
sage: integrate(exp(t)/(t + 1)^2,t,algorithm="giac")
undef

But using giac directly, it can integrate it with no problem

>giac
// Using locale /usr/share/locale/
// en_US.utf8
// /usr/share/locale/
// giac
// UTF-8
// Maximum number of parallel threads 8
Help file /usr/share/giac/doc/en/aide_cas not found
Added 26 synonyms
Welcome to giac readline interface
(c) 2001,2017 B. Parisse & others
Homepage http://www-fourier.ujf-grenoble.fr/~parisse/giac.html
Released under the GPL license 3.0 or above
See http://www.gnu.org for license details
May contain BSD licensed software parts (lapack, atlas, tinymt)
-------------------------------------------------
 0>> integrate(exp(t)/(t + 1)^2,t)
 (t*Ei(t+1)+Ei(t+1)-exp(1)*exp(t))/(t*exp(1)+exp(1))
// Time 0.01
1>>

So why did sage return udef for this result?

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Comments

In 9.3.beta5, giac doesn't solve it when used through integrate :

sage: integrate(exp(t)/(t+1)^2,t, algorithm="giac")
integrate(e^t/(t + 1)^2, t)
sage: integrate(exp(t)/(t+1)^2,t)
-e^(-1)*exp_integral_e(2, -t - 1)/(t + 1)
sage: integrate(exp(t)/(t+1)^2,t, algorithm="sympy")
integrate(e^t/(t + 1)^2, t)
sage: integrate(exp(t)/(t+1)^2,t, algorithm="fricas")
((t + 1)*Ei(t + 1) - e^(t + 1))*e^(-1)/(t + 1)
sage: mathematica.Integrate(exp(t)/(t+1)^2,t)
-(E^t/(1 + t)) + ExpIntegralEi[1 + t]/E

But does when used directly :

sage: %giac integrate(exp(t)/(t + 1)^2,t)
(t*Ei(t+1)+Ei(t+1)-exp(1)*exp(t))/(t*exp(1)+exp(1))

HTH,

Emmanuel Charpentier gravatar imageEmmanuel Charpentier ( 2021-01-03 19:58:39 +0100 )edit
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