Re: Multiple Sums in Mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg53702] Re: Multiple Sums in Mathematica
- From: "Steve Luttrell" <steve_usenet at _removemefirst_luttrell.org.uk>
- Date: Mon, 24 Jan 2005 03:37:23 -0500 (EST)
- References: <csvir2$avi$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Here is an example of what you could do:
With[{m=2,n=4},
Apply[
Sum,
Prepend[
Table[{i[k],m},{k,n}],
Apply[f,Table[i[k],{k,n}]]
]
]
]
f[1,1,1,1]+f[1,1,1,2]+f[1,1,2,1]+f[1,1,2,2]+f[1,2,1,1]+f[1,2,1,2]+f[1,2,2,1]+
f[1,2,2,2]+f[2,1,1,1]+f[2,1,1,2]+f[2,1,2,1]+f[2,1,2,2]+f[2,2,1,1]+
f[2,2,1,2]+f[2,2,2,1]+f[2,2,2,2]
Steve Luttrell
"Sebastian Brandt" <sbrandt at physics.wustl.edu> wrote in message
news:csvir2$avi$1 at smc.vnet.net...
> Hello,
>
> I want to perform a nested sum, where the number of summations is not
> specified. I.e., I am looking for a way to implement the sum
>
> sum[ f, {i1, 1, M}, {i2, 1, M}, ..., {in, 1, M} ]
>
> Does anbody know how to do this for arbitrary n?
>
> Regards,
>
> Sebastian Brandt
>