Re: NInegrate Bug
- To: mathgroup at smc.vnet.net
- Subject: [mg116466] Re: NInegrate Bug
- From: Andrew Moylan <amoylan at wolfram.com>
- Date: Wed, 16 Feb 2011 04:36:01 -0500 (EST)
No, sorry. The fix is not available as a patch for version 7.
Andrew Moylan
Wolfram Research
----- Original Message -----
From: "Kurt TeKolste" <tekolste at fastmail.net>
To: "Andrew Moylan" <amoylan at wolfram.com>, "Mathgroup" <mathgroup at smc.vnet.net>
Sent: Tuesday, February 15, 2011 11:47:43 PM
Subject: [mg116466] Re: [mg116439] NInegrate Bug
Comforting, but expensive. Do you have a patch for 7?
On Tue, 15 Feb 2011 23:17 +1100, "Andrew Moylan" <amoylan at wolfram.com>
wrote:
> Hi Kurt,
>
> You should not encounter any problem in Mathematica 8. E.g.
>
> In[1]:= NIntegrate[Sin[x^2], {x, -5, -2}]
>
> Out[1]= -0.276859
>
> In[2]:= N[Integrate[Sin[x^2], {x, -5, -2}]]
>
> Out[2]= -0.276859
>
> Andrew Moylan
> Wolfram Research
>
>
>
> On Feb 15, 2011, at 10:34 PM, Kurt TeKolste wrote:
>
> > Has there been a resolution of the NIntegrate bug?
> >
> > Apparently NIntegrate produces the negative of the right answer for
> > integrations that start and end to the left of zero -- some of the time.
> > (Cos[x] and Sin[x^2] get the wrong result, Sin[x] is good).
> >
> > Since it is not clear what criterion Mathematica uses in deciding to
> > give the wrong answer it is not clear when to use NIntegrate[] and when
> > to use NIntegrate[*Sign[independent variable]].
> >
> > And this calls into question any results for analysis that uses
> > NIntegrate -- not a happy situation.
> >
> > Kurt TeKolste
> >
>
>