Re: Getting rid of those deprecated Do[] loops?
- To: mathgroup at smc.vnet.net
- Subject: [mg92788] Re: Getting rid of those deprecated Do[] loops?
- From: Raffy <raffy at mac.com>
- Date: Mon, 13 Oct 2008 06:19:39 -0400 (EDT)
- References: <gcsctj$8mj$1@smc.vnet.net>
On Oct 12, 1:36 am, AES <sieg... at stanford.edu> wrote:
> Trying to think of a "two-variable iterator" approach that will let one
> produce the same results as
>
> data = { };
> Do[
> Do[
> data = AppendTo[data, {aa, bb, xx, yy}],
> {bb, 10, 30, 10}],
> {aa, 1, 2}];
> Print[data // TableForm];
>
> without using those universally deprecated (and even worse, nested)
> Do[ ] loops, not to mention the equally deprecated AppendTo[].
>
> Somewhat to my surprise, the construction
>
> Table[{aa = kk[[1]]; bb = kk[[2]]; aa, bb, xx, yy},
> {kk, {{1, 10}, {1, 20}, {1, 30}, {2, 10},=
{2, 20},
> {2,30}}}
> ] // TableForm
>
> using a two-dimensional iterator iterator variable kk, actually does
> this, though the "iterator list" is obviously a bit messy.
>
> Simpler way of defining an iterator to do this? In more than two
> iterator dimensions (aa, bb, cc,...)? (with no functional dependence
> between the values of aa, bb, cc).
>
> Is the concept of a multi-dimensional iterator variable kk mentioned in
> the M6 documentation anywhere? (A search on "Iterate" or "iteration"
> brings up 193 hits at 10 per screen.)
Join @@ Table[{aa, bb, xx, yy}, {bb, {10, 20, 30}}, {aa, {1, 2}}] //
TableForm