Re: NIntegrate with Minimize

*To*: mathgroup at smc.vnet.net*Subject*: [mg53556] Re: [mg53549] NIntegrate with Minimize*From*: "Oz" <x_download at hotmail.com>*Date*: Tue, 18 Jan 2005 05:07:55 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Woops, sorry. The code is ff[a_] := First[Minimize[{x + a, 0 <= x <= 2}, {x}]] NIntegrate[ff[a], {a, 0, 6}] and the problem is that it can't do the Minimize symbolically, which it seems to try to do before putting the value of 'a' in. I have, since posting, found out a way to work around it (thanks to Andrzej Kozlowski), namely putting in ?NumericQ next to the variable in the function definition: ff[a_?NumericQ] := First[Minimize[{x + a, 0 <= x <= 2}, {x}]] NIntegrate[ff[a], {a, 0, 6}] 18. Kind Regards, Oz -----Original Message----- From: DrBob [mailto:drbob at bigfoot.com] To: mathgroup at smc.vnet.net Subject: [mg53556] Re: [mg53549] NIntegrate with Minimize Try posting that in InputForm, so that we can see the code. http://www.eclecticdreams.net/DrBob/copy_as_inputform.htm Bobby On Sun, 16 Jan 2005 22:24:06 -0500 (EST), Oz <x_download at hotmail.com> wrote: > Hiya, > > I'm having trouble performing a numerical integration that involves a > Minimize. I think it might have something to do with HoldAll, but am not > sure how to fix it (couldn't find any actual solutions that worked in > the archives). Any help most appreciated. Here is a simplified version > of the code (the function and constraints I'm actually using are more > complicated): > > ff[a_] := First[Minimize[{x + a, 0 â?¤ x â?¤ 2}, {x}]] > NIntegrate[ff[a], {a, 0, 6}] > > Mathematica raises a Minimize::objv error, complaining that a+x contains > a nonconstant expression independent of x, and so the NIntegrate fails. > Ideas? > > Thanks, > Oz > > > > > -- DrBob at bigfoot.com www.eclecticdreams.net