Re: programming comptition II (correction)
- To: mathgroup at smc.vnet.net
- Subject: [mg5051] Re: [mg5043] programming comptition II (correction)
- From: fransm at win.tue.nl (Frans Martens)
- Date: Wed, 23 Oct 1996 01:38:12 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Hello,
My previous solution of Problem One was wrong.
The wrong solution is with the example:
li1 = Array[f, {2,3,4}]
li2 = Array[g, {2,3,4}]
Times[li1,li2]
A solution is
MapThread[List,{li1,li2},Length[Dimensions[li1]]]
Frans Martens
Eindhoven University of Technology
The Netherlands
Begin forwarded message:
>From: Xah Lee <xah at best.com>
>Subject: [mg5043] programming comptition II
Two pure programing problems some of you will enjoy.
Problem One: Constructing Dimensions.
Given a one dimensional list, how to partition it so it becomes a
nested
list with a specified Dimensions. Example and solution:
Array[f, {5,2,3}]
First@ Fold[Partition, Flatten@ %, Reverse at {5,2,3} ]
%% === %
--------------------------------------
Problem Two: Pairing of Nodes.
Given two list of the same Dimensions, how to combine the list so
that
the end nodes of the new list pair the end nodes of given lists.
Example
and solution:
Clear[li1, li2]
li1 = Array[f, {2,3,4}]
li2 = Array[g, {2,3,4}]
Transpose[ {li1, li2},
RotateRight@ Range@ Length@ Dimensions@ {li1, li2}
]
--------------------------------------
Please post your alternative approach.
Xah
xah at best.com; 74631.731 at compuserve.com
http://www.best.com/~xah/SpecialPlaneCurves_dir/specialPlaneCurves.ht
ml
Mountain View, CA, USA