Re: Sorting by date
- To: mathgroup at smc.vnet.net
- Subject: [mg72664] Re: [mg72637] Sorting by date
- From: "Adriano Pascoletti" <pascolet at dimi.uniud.it>
- Date: Sun, 14 Jan 2007 04:42:46 -0500 (EST)
Clifford Martin wrote .. > Hi All, > > I have a list of lists that looks like so: > > > {{3, 137.5, 13978, {2005, 2, 8}}, {3, 138.5, 12519, {2005, 1, 4}}, {3, > 171.9, 15835, {2005, 4, 12}}, {3, 142.8, 17137, {2005, 11, 19}}, > {3, 161.1, 18881, {2006, 1, 18}}, {3, 108.7, 20055, {2006, 2, 28}}, {3, > 157, 21498, {2006, 9, 14}}, {3, 118.1, 10891, {2004, 11, 12}}} > > The last element per vector is a date. I'd like to sort the list so that > the vectors are arranged in ascending order of date, i.e. the vector containing > {2004,11,12} should be first and and the vector containing {2006,9,14} > should be last. Any help would be appreciated. > Clifford, Sort using the canonical ordering (OrderedQ[....]) on the last element of each list: In[1]:= list = {{3, 137.5, 13978, {2005, 2, 8}}, {3, 138.5, 12519, {2005, 1, 4}}, {3, 171.9, 15835, {2005, 4, 12}}, {3, 142.8, 17137, {2005, 11, 19}}, {3, 161.1, 18881, {2006, 1, 18}}, {3, 108.7, 20055, {2006, 2, 28}}, {3, 157, 21498, {2006, 9, 14}}, {3, 118.1, 10891, {2004, 11, 12}}}; In[2]:= Sort[list, OrderedQ[{#1[[-1]], #2[[-1]]}] & ] Out[2]= {{3, 118.1, 10891, {2004, 11, 12}}, {3, 138.5, 12519, {2005, 1, 4}}, {3, 137.5, 13978, {2005, 2, 8}}, {3, 171.9, 15835, {2005, 4, 12}}, {3, 142.8, 17137, {2005, 11, 19}}, {3, 161.1, 18881, {2006, 1, 18}}, {3, 108.7, 20055, {2006, 2, 28}}, {3, 157, 21498, {2006, 9, 14}}} Adriano Pascoletti