Re: Hold[] ReleaseHold[] ? or what ?
- To: mathgroup at smc.vnet.net
- Subject: [mg60201] Re: [mg60168] Hold[] ReleaseHold[] ? or what ?
- From: Chris Chiasson <chris.chiasson at gmail.com>
- Date: Wed, 7 Sep 2005 04:03:59 -0400 (EDT)
- References: <200509060227.WAA25742@smc.vnet.net>
- Reply-to: chris.chiasson at gmail.com
- Sender: owner-wri-mathgroup at wolfram.com
In the second input, NIntegrate is called with an integrand that has
non numeric "constants of integration". In the first input, the
Pattern for the argument of f prevents that situation from occurring.
On 9/5/05, lupos <lupos at cheerful.com> wrote:
> hi all,
>
> why does the following code work as hoped ?
>
> In[1]
> fn[u_Real] := NIntegrate[Sin[x + u], {x, 1, 2}];
> FindMinimum[fn[u], {u, 0}]
>
> Out[2]=
> {-0.9588510772084058, {u -> -3.070796346594197}}
>
>
>
> but the next line generates some warnings/errors altough calculating
> correctly.
> how can the situation be fixed in a nice way ?
> maybe some Hold[] / ReleaseHold[] ?
>
> In[3]:=
> FindMinimum[NIntegrate[Sin[x + u], {x, 1, 2}], {u, 0}]
>
> Out[3]:=
> NIntegrate::inum : Integrand Sin[u+x] is not numerical at {x} = {1.5`}.
> NIntegrate::inum : Integrand Sin[u+x] is not numerical at {x} = {1.5`}.
> NIntegrate::inum : Integrand Sin[u+x] is not numerical at {x} = {1.5`}.
> {-0.958851077208406, {u -> -3.0707963268148295}}
>
>
> thanks for any hints
> robert.
>
>
--
Chris Chiasson
http://chrischiasson.com/
1 (810) 265-3161
- References:
- Hold[] ReleaseHold[] ? or what ?
- From: "lupos" <lupos@cheerful.com>
- Hold[] ReleaseHold[] ? or what ?