Re: SortBy won't order irrationals
- To: mathgroup at smc.vnet.net
- Subject: [mg124046] Re: SortBy won't order irrationals
- From: Shizu <slivo.vitz at msa.hinet.net>
- Date: Sat, 7 Jan 2012 05:18:26 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
It's normal, since Mathematica sorts by structure. This could be a simple solution: In[]:= Sort[ptsIrr, #1[[2]] < #2[[2]] &] Out[]:= {{-1, 0}, {7, 0}, {Sqrt[3], 1}, {6, 1}, {Sqrt[5], 1}, {4, 1}, {1, Sqrt[2]}, {2, 2}, {0, 2}} This sorts by structure: In[]:= Sort[{Pi, E, 2, 3, 1, Sqrt[2]}] Out[]:= {1, 2, 3, Sqrt[2], E, \[Pi]} This sorts by numerical values: In[]:= Sort[{Pi, E, 2, 3, 1, Sqrt[2]}, Less] Out[]:= {1, Sqrt[2], 2, E, 3, \[Pi]} With SortBy[], simply you have to N[] as you did.