Custom sorting via ordering list
- To: mathgroup at smc.vnet.net
- Subject: [mg124158] Custom sorting via ordering list
- From: Chris Young <cy56 at comcast.net>
- Date: Wed, 11 Jan 2012 04:24:43 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
Don't really need the matrix I had in my previous post, just the sort
specification. All the upper-triangular matrix did was to ensure there
was a less-than-or-equal relation, and we're taking care of that by
simply testing pairs of elements to make sure they're in the same
left-to-right order as they are in the "sorted" list we specify in the
in_order function.
In[839]:= in\[HorizontalLine]order2[e1_, e2_] :=
Module[
{sorted},
sorted = {1, 2, a, b, A, B};
Position[sorted, e1][[1, 1]] <= Position[sorted, e2][[1, 1]]
]
In[840]:= Sort[list, {e1, e2} \[Function] in\[HorizontalLine]order2[e1, e2]]
Out[840]= {1, 2, a, b, A, B}
In[841]:= Sort[{B, a, 1, b, b, 1}, {e1, e2} \[Function]
in\[HorizontalLine]order2[e1, e2]]
Out[841]= {1, 1, a, b, b, B}