Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2007
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

A Bug or not a bug?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg74883] A Bug or not a bug?
  • From: "dimitris" <dimmechan at yahoo.com>
  • Date: Tue, 10 Apr 2007 05:12:45 -0400 (EDT)

This appears in another forum.
(Actually the third integral below. The discoverer regards it as a
bug.
The first two integrals are part of my response to him).

Integrate[Exp[x], {x, -Infinity, 0}] (*correct*)
1

Integrate[Exp[x], {x, 0, Infinity}]  (*correct*)
Integrate::idiv: Integral of E^x does not converge on {0, Infinity}.
Integrate[Exp[x], {x, 0, Infinity}]

Integrate[Exp[x], {x, -Infinity, 0}, Assumptions -> x < 0]
(*incorrect*)
Integrate::idiv: Integral of E^(-x) does not converge on
{0,Infinity}.
Integrate[E^x, {x, -Infinity, 0}, Assumptions -> x < 0]

Since my experience about what must be regarded as a bug/feature is
not so
big as others in this forum I would like to see what you think about
the last
performance of Mathematica.

I personally don't regard it as a serious bug. It is like trying to
"cheat" Mathematica.
I am sure there are a great many ways to make built in functions to
give wrong results!
And what is more important the unecessary setting of Assumptions
caused it!

Your Opinion?

Dimitris



  • Prev by Date: RootSum 2
  • Next by Date: Re: Length of random index into list
  • Previous by thread: RootSum 2
  • Next by thread: Job opportunities at Wolfram Research