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Re: Procmail fractional scoring screwed up.

2003-03-10 11:55:19
On Thu, 6 Mar 2003, Daryle A. Tilroe wrote:

John's 'good' value of .11  for a base doesn't work on my
version of procmail/redhat.  It actually gives bad results
and .1 gives the correct ones.  E.G. .1^1 with 100 matches
gives 10 but .11^1 with 100 matches gives <1.

I got curious and tried this with my procmail 3.22, RH Linux 6.2.
With the same input every time:

* 1^1 xx        Score:     100     100 "xx"

* .1^1 xx       Score:       9       9 "xx"

* .11^1 xx      Score:      10      10 "xx"

* .2^1 xx       Score:      19      19 "xx"

* 1^.9 xx       Score:       1       1 "xx"

* 10^.9 xx      Score:      91      91 "xx"

* 100^0.09 xx   Score:     109     109 "xx"

* 100^0.009 xx  Score:     100     100 "xx"

I'm only guessing, but I'd suspect a rounding error when storing the
intermediate value between matches.  Different floating point precision
could explain why Daryle's results vary so much more wildly than mine,
and why it differs for different exponent values.


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