[18787] in s-news-athena
[S] Help eliminate a recursive function
daemon@ATHENA.MIT.EDU (David E. Moore)
Thu Jul 29 16:40:45 1999
From: "David E. Moore" <moordi@email.uc.edu>
To: <s-news@wubios.wustl.edu>
Date: Tue, 27 Jul 1999 16:58:21 -0400
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Dear S-Plus programmers,
I have a simple problem for a recursive function that understandably
blows up in S+. I would really appreciate it, therefore, if someone
could show me how to code around the recursion. Here's the problem:
I want to generate every possible combination of n elements from a
given vector. For example, every possible combination of 5 numbers
taken from the sequence 1:10. I then need to process each and every
combination before proceeding to the next one. Thus, while I need to
perform some operations on each combination, I don't need (nor want)
to store them all.
The reason I need an alternative approach is that I'm working with
very large numbers. The number of combinations quickly becomes
unmanageable using every approach that I've tried, so I'm hoping
someone who knows S+ can show me how this can be done in an
efficient manner. I will happily provide whatever details seem
necessary to identify the particular S+ practices that might be
relevant to my problem. Thanks for any suggestions.
David Moore
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