Re: Possible simple bug in NMaximize

*To*: mathgroup at smc.vnet.net*Subject*: [mg71090] Re: [mg71040] Possible simple bug in NMaximize*From*: Nick Grishin <grishin at chop.swmed.edu>*Date*: Wed, 8 Nov 2006 06:14:23 -0500 (EST)*References*: <200611060752.CAA08685@smc.vnet.net> <385666A3-8452-4267-9A16-51F52DC79904@mimuw.edu.pl> <AD156707-E97C-4D2A-8251-A2FD989FC235@mimuw.edu.pl>

> On 6 Nov 2006, at 19:05, Andrzej Kozlowski wrote: > >> >> On 6 Nov 2006, at 16:52, Nick Grishin wrote: >> >>> (* does not work *) >>> func = Hold[NIntegrate[t^3, {t, x, 0}]]; >>> NMaximize[func, x] >>> >>> (* works *) >>> func = Hold[NIntegrate[t^3, {t, 0, x}]]; >>> NMinimize[func, x] >>> >>> $Version >>> 5.2 for Microsoft Windows (June 20, 2005) >>> >> >> A bug in NMaximize? Why? It behaves exactly as it should do with this kind >> of input. The problem is with MMinimize, because you when you give it >> nonsensical input it actually produces output, which unfortunately (by >> sheer accident), looks as if it might be right. But it is nonssense >> nonetheless (nonsense in - > nonsense out) nonsensical, and to convince >> you of it I will slightly change your input: >> >> func = Hold[NIntegrate[t^3, {t, 10, x}]]; >> >> >> NMinimize[func, x] >> >> >> {-2500.0000000000005, {x -> -0.0002833987269403981}} >> >> Now, does this look like it "works"? >> >> Andrzej Kozlowski > > > I have to admit that my example was pointless; it does also "work" just as > much as your example works, although it should not. I agree that seeing this This I understand. n

**References**:**Possible simple bug in NMaximize***From:*Nick Grishin <grishin@chop.swmed.edu>