Re: product formula in mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg68797] Re: product formula in mathematica
- From: Peter Pein <petsie at dordos.net>
- Date: Fri, 18 Aug 2006 03:13:00 -0400 (EDT)
- References: <ec19d4$oie$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
frou schrieb:
> 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
>
The first method works for arbitrary lists:
In[1]:= Times@@(f/@{1,3,4,9})
Out[1]= f[1] f[3] f[4] f[9]
and the second is very specialized ;-)
In[2]:= Product[f[FromDigits[IntegerDigits[k,2],3]],{k,4}]
Out[2]= f[1] f[3] f[4] f[9]
(just kidding - sorry)
Peter