Re: Sorting question
- To: mathgroup at smc.vnet.net
- Subject: [mg52772] Re: Sorting question
- From: "Dr. Wolfgang Hintze" <weh at snafu.de>
- Date: Mon, 13 Dec 2004 04:22:13 -0500 (EST)
- References: <cpeko6$764$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Assuming that "out of order with" means unequal here's an approach using
Select.
Let your list be
In[33]:=
d = {{1, 1}, {2, 3}, {3, 2}, {4, 4}}
Out[33]=
{{1, 1}, {2, 3}, {3, 2}, {4, 4}}
Then
In[32]:=
s = Select[d, #1[[1]] == #1[[2]] & ]
Out[32]=
{{1, 1}, {4, 4}}
Hope this helps.
Wolfgang
"out of order with"
Nimrod wrote:
> A simple sorting question that has me stumped as to how to do it both
> quickly and elegantly.
>
> I have a list of data pairs of the form (distance, time). I want to
> sort on the distance element and then remove all pairs where the time
> element is out of order with the distance element. For example
> ((1,1),(2,3),(3,2),(4,4)) --> ((1,1),(4,4)). The actual lists are
> much longer.
>
> Thanks in advnace,
>
> Nimrod.
>
>