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Refactor of math.statistics

db4
Aaron Schaefer 2008-11-09 17:16:30 -05:00
parent 326ce8c71b
commit f20ab6f4e8
1 changed files with 8 additions and 8 deletions
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extra/math/statistics/statistics.factor
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@ -1,7 +1,7 @@
! Copyright (C) 2008 Doug Coleman, Michael Judge. ! Copyright (C) 2008 Doug Coleman, Michael Judge.
! See http://factorcode.org/license.txt for BSD license. ! See http://factorcode.org/license.txt for BSD license.
USING: kernel math math.analysis math.functions math.vectors sequences USING: arrays kernel math math.analysis math.functions sequences sequences.lib
sequences.lib sorting ; sorting ;
IN: math.statistics IN: math.statistics
: mean ( seq -- n ) : mean ( seq -- n )
@ -19,10 +19,10 @@ IN: math.statistics
: median ( seq -- n ) : median ( seq -- n )
#! middle number if odd, avg of two middle numbers if even #! middle number if odd, avg of two middle numbers if even
natural-sort dup length dup even? [ natural-sort dup length even? [
1- 2 / swap [ nth ] [ [ 1+ ] dip nth ] 2bi + 2 / [ midpoint@ dup 1- 2array ] keep nths mean
] [ ] [
2 / swap nth [ midpoint@ ] keep nth
] if ; ] if ;
: range ( seq -- n ) : range ( seq -- n )
@ -44,14 +44,14 @@ IN: math.statistics
: ste ( seq -- x ) : ste ( seq -- x )
#! standard error, standard deviation / sqrt ( length of sequence ) #! standard error, standard deviation / sqrt ( length of sequence )
dup std swap length sqrt / ; [ std ] [ length ] bi sqrt / ;
: ((r)) ( mean(x) mean(y) {x} {y} -- (r) ) : ((r)) ( mean(x) mean(y) {x} {y} -- (r) )
! finds sigma((xi-mean(x))(yi-mean(y)) ! finds sigma((xi-mean(x))(yi-mean(y))
0 [ [ >r pick r> swap - ] bi@ * + ] 2reduce 2nip ; 0 [ [ [ pick ] dip swap - ] bi@ * + ] 2reduce 2nip ;
: (r) ( mean(x) mean(y) {x} {y} sx sy -- r ) : (r) ( mean(x) mean(y) {x} {y} sx sy -- r )
* recip >r [ ((r)) ] keep length 1- / r> * ; * recip [ [ ((r)) ] keep length 1- / ] dip * ;
: [r] ( {{x,y}...} -- mean(x) mean(y) {x} {y} sx sy ) : [r] ( {{x,y}...} -- mean(x) mean(y) {x} {y} sx sy )
first2 [ [ [ mean ] bi@ ] 2keep ] 2keep [ std ] bi@ ; first2 [ [ [ mean ] bi@ ] 2keep ] 2keep [ std ] bi@ ;