Re: product formula in mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg68753] Re: product formula in mathematica*From*: "Norbert Marxer" <marxer at mec.li>*Date*: Fri, 18 Aug 2006 03:11:56 -0400 (EDT)*References*: <ec19d4$oie$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hello The iterator (i.e. the second argument of Product) has to be a standard iterator. Therefore your input will not work. But you can write your own product function, which does what you want. If you define myProduct[f_, arr_] := Apply[Times, Thread[f[arr]]] Then myProduct[Sin, {1, 3, 4, 9, 12}] will give Sin[1] Sin[3] Sin[4] Sin[9] Sin[12] Best Regards Norbert Marxer www.mec.li 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. > > Thanks