Re: Sorting point-arrays by rows and columns, cont.

*To*: mathgroup at smc.vnet.net*Subject*: [mg124126] Re: Sorting point-arrays by rows and columns, cont.*From*: Shizu <slivo.vitz at msa.hinet.net>*Date*: Tue, 10 Jan 2012 05:58:15 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

> Thanks to Fred Simons for this method. Seems to work > fine and seems to > be one of the simplest to use in this particular > case. Still wish that > Sort would just accept a list of successive > conditions to break ties, > as SortBy does. (SortBy, however, applies the > functions to every > element and _then_ sorts, not what we want here.) > > In[3]:= Sort[hexPts, #1[[2]] < #2[[ > 2]] \[Or] (#1[[2]] == #2[[2]] && #1[[1]] <= > ]] <= #2[[1]]) & ] > > Out[3]= {{-(1/2), -(Sqrt[3]/2)}, {1/2, -(Sqrt[3]/2)}, > {-1, 0}, {0, > 0}, {1, 0}, {-(1/2), Sqrt[3]/2}, {1/2, Sqrt[3]/2}} > Finally, I understood what Chris wanted -- you wanted to sort by Y and then X coordinates. I think Fred's method is the most elegant so far. My procedure is kind of complex, so I didn't post it here. What Chris expected from Mathematica doesn't exist. And so, you may want to invent your own Sort[] or amend the original Sort[] or SortBy[], and share the result with us?