Re: Getting rid of those deprecated Do[] loops?
- To: mathgroup at smc.vnet.net
- Subject: [mg92777] Re: Getting rid of those deprecated Do[] loops?
- From: "sjoerd.c.devries at gmail.com" <sjoerd.c.devries at gmail.com>
- Date: Mon, 13 Oct 2008 06:17:40 -0400 (EDT)
- References: <gcsctj$8mj$1@smc.vnet.net>
Multidimensional iteration is the sixth of the possible formats
described in the documentation of the Table and Do functions. The
construction that surprised you is the fifth one. Actually, you are
able to iterate over an arbitrary list of objects.
Cheers -- Sjoerd
On Oct 12, 10:36 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.)