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Re: How to sort elements from a two-dimensional list

• To: mathgroup at smc.vnet.net
• Subject: [mg123295] Re: How to sort elements from a two-dimensional list
• From: Ulrich Arndt <ulrich.arndt at data2knowledge.de>
• Date: Wed, 30 Nov 2011 07:04:40 -0500 (EST)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <201111300822.DAA17198@smc.vnet.net>

Do you want to distinguish 1 and 1. ?

If NOT this should do.

sort = Sort[data, First[#1] < First[#2] &]
Map[{#[[1, 1]], #[[All, 2]]} &, Split[sort, First[#1] == First[#2] &]]

or

Map[{#[[1, 1]], #[[All, 2]]} &, SplitBy[N[sort], First]]

if you want to distinguish x and x.

this should do

sort = Sort[data, First[#1] === First[#2] &]
Map[{#[[1, 1]], #[[All, 2]]} &,
 Split[sort, First[#1] === First[#2] &]]

Ulrich

Am 30.11.2011 um 09:22 schrieb Pippo:

> data={{1,0.0000317057}, {1,0.0000156821}, {1,0},{1, 00000234685},{1,0.000025413}, {1., 0.0000249271},{1, 0.0000210391}, {1.,0.0000181187},{1,0.0000210391},{2, 0.000025413}, {2.,0.000024441},{2,0.0000224955}, {2,0.0000239548}, {2,0.0000234685},{2,0.0000215261},{2,0.0000132381},{2,0.0000346042},{2,0.0000336413},{3,0.0000355749}, {3,0.0000302568},{3,0.0000297722},{3, 0.000025413}, {3,0.0000239548},{3,0.0000268658}, {3,0.0000239548}, {3,0.0000273512}, {3., 0.0000273512}, {3., 0.0000142161}, {4,0.0000190941}};

• References:
  • How to sort elements from a two-dimensional list
    • From: Pippo <dinodeblasio@yahoo.it>