Hi Ivo,
>>>>> "IU" == Ivo Ugrina <[EMAIL PROTECTED]>
>>>>> on Fri, 14 Dec 2007 23:03:37 +0100 writes:
IU> I took some time and liberty and tried to improve
IU> existing implementation of SignRank functions
IU> in R. (dsignrank, ...)
IU> As I have seen they've been based on csignrank.
IU> So I modified csignrank and, I believe,
IU> improved calculation time and memory efficiency.
do you have evidence for your belief?
i.e. a set of system.time(.) calls where you see the
difference?
IU> The idea is basically the same. I use the same recursion
IU> as original author
(Kurt Hornik)
IU> used with one slight modification.
IU> I am generating Wilcoxon SignRank density from the
IU> beginning (for n=2,3,...) with the help of recursion formula.
IU> What is changed?
IU> There is no need for SINGRANK_MAX in src/nmath/nmath.h anymore.
IU> Only functions:
IU> static void w_free()
IU> void signrank_free()
IU> static void w_init_maybe(int n)
IU> static double csignrank(int k, int n)
IU> in src/nmath/signrank.c have been altered.
IU> There was no change to dsignrank, psignrank, ...
IU> I've tried to make as little changes as possible.
IU> So, to compile with new functions only src/nmath/signrank.c
IU> needs to be changed with the one given in attachment.
IU> I hope it really is an improvement.
Me too :-) {Waiting for your test results}
The code does look slightly simpler, I agree.
BTW: If you had a smart idea to *not* use a static 'w' and still
be memory efficient,
that could lead to make that code "thread-safe", but I am
not at all sure this is possible without using
"thread-library C code".
Martin
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