Re: NInegrate Bug

*To*: mathgroup at smc.vnet.net*Subject*: [mg116472] Re: NInegrate Bug*From*: "Kurt TeKolste" <tekolste at fastmail.net>*Date*: Wed, 16 Feb 2011 04:37:06 -0500 (EST)

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 > > > >