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>
- Possible simple bug in NMaximize