n n k-1 x - 1 w * Sum x = w * ------- k=1 x - 1
x=0 | Only the first match will contribute w to the score. Any subsequent matches are ignored. |
x=1 | Every match will contribute the same w to the score. The score grows linearly with the number of matches found. |
0<x<1 | Every match will contribute less to the score than the previous one. The score will asymptotically approach a certain value (see the NOTES section below). |
1<x | Every match will contribute more to the score than the previous one. The score will grow exponen- tionally. |
x<0 | Can be utilised to favour odd or even number of matches. |
* w^x > L
x / M \ w * | --- | \ L /
* w^x < L
x / L \ w * | --- | \ M /
:0 Bh * -150^0 * 1^1 ^.*$ /dev/null
:0 HB * !^Precedence:.*(junk|bulk) * 2000^0 ^From:.*(john@home|claire@work) * 2000^0 ^Subject:.*meeting * 300^0 ^Subject:.*Re: * 1000^.75 elvis|presley * -100^1 ^> * 350^.9 :-\) * -500^0 ^From:.*(boss|jane|henry)@work * -100^3 > 2000 priority_folder
:0 ^From mailinglist-request@some.where { :0: * ^(From:.*(paula|bill)|Subject:.*skiing) mailinglist :0 Bh * 20^1 ^> * -10^1 ^[^>] /dev/null :0: mailinglist }
.* | will always match a zero length string at the same
spot. |
.+ | will always match one character (except newlines of course). |
w ------- 1 - x In order to reach half the maximum value you need - ln 2 n = -------- ln x