Re: vector integration
- To: mathgroup at smc.vnet.net
- Subject: [mg35074] Re: vector integration
- From: Peter <petsie at arcor.de>
- Date: Mon, 24 Jun 2002 03:20:57 -0400 (EDT)
- References: <aeu8uv$8kd$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Michael Bechmann wrote:
> hello everybody,
> i am facing a problem in the numerical integration of a vector-valued
> function using Mathematica.
> as the result of some operation on the variable x defined by f[x_]=...
> i get a list of numbers {f1,f2,f3,...,fn} each of which depends on the
> variable x.
> the bad point is that the fi can not be evaluated one by one. for some
> chosen value of x i can only calculate the whole list of the fis.
> now i need to integrate each of the fis over x. of course i could
> intgrate each list element separately using NIntegrate:
>
> Fi=NIntegrate[f[x][[i]],{x,x1,x2}]
>
> but since the evaluation of the list f[x] is very time consuming i would
> like to somehow integrate the whole list at once which is not possible
> with NIntegrate.
>
> did anybody encounter this problem, too? does anybody know a useful
> package or any solution?
>
> thanks.
>
>
Hi Michael,
F = NIntegrate[#, {x, x1, x2}]& /@ f[x]
or equiv.
F = Map[ NIntegrate[#, {x, x1, x2}]&, f[x] ]
should do what you want.
Peter