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

*To*: mathgroup at smc.vnet.net*Subject*: [mg123298] Re: How to sort elements from a two-dimensional list*From*: A Retey <awnl at gmx-topmail.de>*Date*: Wed, 30 Nov 2011 07:05:12 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jb4pga$gts$1@smc.vnet.net>

Hi, > I have a list as follows: > 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}}; > > I'd like to know how to reduce the number of terms of the list to avoid the terms on the right side {xi,..} to be repeated. > you could use Union, but probably this is even more adequat: DeleteDuplicates[data] since you are comparing real numbers, you might want to use a more elaborate test, e.g. something like: DeleteDuplicates[data, And[Abs[#1[[1]] - #2[[1]]] < 0.5, Abs[#1[[2]] - #2[[2]]] < 10^-6] &] hth, albert