Re: Sorting 3 points
- To: mathgroup at smc.vnet.net
- Subject: [mg87967] Re: [mg87935] Sorting 3 points
- From: "Maarten van der Burgt" <maarten.vanderburgt at icos.be>
- Date: Mon, 21 Apr 2008 06:37:44 -0400 (EDT)
Carlos,
This is the last of the 'basic examples' from the Help on Sort:
In: Sort[{{a,2},{c,1},{d,3}},#1[[2]]<#2[[2]]&]
Out: {{c,1},{a,2},{d,3}}
The sorting function is
#1[[2]]<#2[[2]]&
It should be easy to work out from this what you have to modify in this
sorting function to achieve the results you want.
Regards,
Maarten
carlos@Colora
do.EDU To: mathgroup at smc.vnet.net
cc:
21/04/2008 Subject: [mg87935] Sorting 3 points
09:21
Simple question, but documentation is no help.
I have three coordinate triplets:
P1={x1,y1,z1} P2={x2,y2,z2} P3={x3,y3,z3}
where all entries are numeric. I wont to sort them into
P1s={xs1,ys1,zs1} P2s={xs2,ys2,zs2} P3s={xs3,ys3,zs3}
so that zs3>=zs2>=zs1, with one command
{P1s,P2s,P3s}=Sort[{P1,P2,P3}, Ordering Function]
Is that possible and if so, which Ordering Function
should be used? Thanks.