[R] 2 questions regarding base-n and identifing digits + the source problem description

Andrej Kveder andrejk at zrc-sazu.si
Thu Oct 9 10:09:22 CEST 2003


Thanks for the suggestions..

The strsplit function works great for the second question...
I will have to come up with another solution to the first one, since my
problem would definetly involve a lot of calculations and I think that
current methods would cause major computational congestion...
BUt here is the outline of my problem... if anybody has an idea...
 In practice I start with 4 possible correlations: -0.9, -0.1, 0.1, 0.9 and
want to construct all possible 3x3 correaltion matrices with those values.
So I need to do all possible permutations of a given length with
replication. I have a set of 4 distinct values and want to create the
permutations of length 3.
My idea was as folows: specifing the sequence in base-4 form 0 to 333 would
account for all possible combinations.
I checked some of the existing functions which were either recursive and
slow or without replication. I think there was a thread on the list just a
short while ago.
If anybody has a hint to follow, i would be more then glad to try it out...

Thanks again

Andrej

_________
Andrej Kveder, M.A.
researcher
Institute of Medical Sciences SRS SASA; Novi trg 2, SI-1000 Ljubljana,
Slovenia
phone: +386 1 47 06 440   fax: +386 1 42 61 493




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