Re: element selection
- To: mathgroup at smc.vnet.net
- Subject: [mg53623] Re: element selection
- From: Roland Franzius <roland.franzius at uos.de>
- Date: Fri, 21 Jan 2005 06:35:27 -0500 (EST)
- Organization: Universitaet Hannover
- References: <csnt7e$4ec$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Bruyndonckx P. wrote:
> I have two long sorted lists of Integers. If the difference between a number in list 1 and a
> number in list 2 is less than a certain value, both are selected to create a couple. I am
> looking for a fast way to go through both lists and extract these elements to create a new list
> of couples. I tried a number of things, but all of them were rather slow so I need some expert
> advice here.
Depends on your task. If you want pairs at the same index position
Select[Transpose[{list1,list2}],(Abs[Subtract@@#]<crit&)]
If you want all possible ordered pairs
replace "Transpose[{list1,list2}]" by
"Flatten[Outer[pair,list1,list2]]"
--
Roland Franzius