Re: special iterator
- To: mathgroup at smc.vnet.net
- Subject: [mg120685] Re: special iterator
- From: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>
- Date: Wed, 3 Aug 2011 19:19:54 -0400 (EDT)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <j15773$b4v$1@smc.vnet.net>
On Aug 1, 5:40 am, lorenzo <lorenzo_... at yahoo.it> wrote:
> Thanks for all the answers,
>
> I used Delete, apparently it returns a list without the j-th element and
the original list is not affected by any side effect:
>
> wi = Function[{x, j, func, data},
> Product[func[x - Delete[data, j][[i]]],
> {i, 1, Length[data] - 1}]];
You said: "...and the original list is not affected by any side
effect:"
That's not surprising as it is true for many / most functions working
on some argument: they work on a copy of the argument and return a
copy too. Exceptions are functions like AppendTo and the like.
Cheers --Sjoerd