Re: product formula in mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg68782] Re: product formula in mathematica
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Fri, 18 Aug 2006 03:12:39 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- References: <ec19d4$oie$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
frou wrote:
> Hi I am interested in doing a product over a set of indices that are
> not continuous
> Product [ f(x_i) , { x_i, 1,3,4,9}] Is this possible it appears
> that the iterator wouldonly take sequences such as 1...10 etc.
Times @@ MapThread[f[Subscript[x, #1]] & , {{1, 3, 4, 9}}]
--> f[Subscript[x, 1]]*f[Subscript[x, 3]]*f[Subscript[x,
4]]*f[Subscript[x, 9]]
Times @@ MapThread[f[x[#1]] & , {{1, 3, 4, 9}}]
--> f[x[1]]*f[x[3]]*f[x[4]]*f[x[9]]
http://documents.wolfram.com/mathematica/functions/Apply
http://documents.wolfram.com/mathematica/functions/MapThread
HTH,
Jean-Marc