Re: sort and positon matrix element help
- To: mathgroup at smc.vnet.net
- Subject: [mg73064] Re: sort and positon matrix element help
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Thu, 1 Feb 2007 02:46:47 -0500 (EST)
- Organization: The University of Western Australia
- References: <epp6nn$dcl$1@smc.vnet.net>
In article <epp6nn$dcl$1 at smc.vnet.net>,
"comp.soft-sys.math.mathematica" <phdrelated at gmail.com> wrote:
> I have a large matrix(m*n). I wanna to sort out the matrix
> from large to small according to its element's value AND save the
> corresponding row and column number as its position.
Here is one way using SparseArray, ArrayRules, and Sort:
SeedRandom[10]
mat = Table[Random[Real, {-100, 100}], {10}, {15}];
Sort[Most[ArrayRules[SparseArray[mat]]], Last[#2] < Last[#1] & ]
{{3, 5} -> 99.1349, {10, 3} -> 98.9494, ...}
Cheers,
Paul
_______________________________________________________________________
Paul Abbott Phone: 61 8 6488 2734
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