Re: Find index of maximal element in multi-dimensional array
- To: mathgroup at smc.vnet.net
- Subject: [mg73522] Re: Find index of maximal element in multi-dimensional array
- From: "Norbert Marxer" <marxer at mec.li>
- Date: Wed, 21 Feb 2007 01:42:20 -0500 (EST)
- References: <erelbt$7h4$1@smc.vnet.net>
On 20 Feb., 12:17, "Andrew Moylan" <andrew.j.moy... at gmail.com> wrote:
> Hi all,
>
> Here's a two-dimensional array of numbers:
>
> z = Table[Random[], {5}, {6}]
>
> What's an efficient way of finding the index of the maximal element of
> z? Here's one way:
>
> Last[Sort[Flatten[MapIndexed[{#2, #1} & , z, {2}], 1],
> OrderedQ[{#1[[2]], #2[[2]]}] & ]]
>
> The output is like this:
>
> {{5, 4}, 0.921344}
>
> But it's so untidy. Any better ideas?
>
> Cheers,
>
> Andrew
Hi Andrew
You can use
Position[z, Max[z]]
if you just want the index. Or you can use
{Position[z, m = Max[z]], m}
if you want both the index and the value.
Best Regards
Norbert Marxer
www.mec.li