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refactor mersenne-twister to not use new-effects

db4
erg 2008-03-30 18:22:35 -05:00
parent 5b0f6907fb
commit c30a8a68ee
1 changed files with 20 additions and 18 deletions
extra/random/mersenne-twister

38
extra/random/mersenne-twister/mersenne-twister.factor
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@ -4,11 +4,14 @@
! http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/CODES/mt19937ar.c
USING: arrays kernel math namespaces sequences system init
accessors math.ranges new-effects random ;
accessors math.ranges random ;
IN: random.mersenne-twister
<PRIVATE
: curry2 ( w quot1 quot2 -- quot1 quot2 )
>r over r> [ curry ] 2bi@ ;
TUPLE: mersenne-twister seq i ;
: mt-n 624 ; inline
@ -19,34 +22,33 @@ TUPLE: mersenne-twister seq i ;
: wrap ( x n -- y ) 2dup >= [ - ] [ drop ] if ; inline
: mt-wrap ( x -- y ) mt-n wrap ; inline
: set-generated ( mt y from-elt to -- )
>r >r [ 2/ ] [ odd? mt-a 0 ? ] bi
r> bitxor bitxor r> new-set-nth drop ; inline
: set-generated ( y from-elt to seq -- )
>r >r >r [ 2/ ] [ odd? mt-a 0 ? ] bi
r> bitxor bitxor r> r> set-nth ; inline
: calculate-y ( mt y1 y2 -- y )
>r over r>
[ new-nth mt-hi ] [ new-nth mt-lo ] 2bi* bitor ; inline
: calculate-y ( y1 y2 mt -- y )
[ nth mt-hi ] [ nth mt-lo ] curry2 bi* bitor ; inline
: (mt-generate) ( mt-seq n -- y to from-elt )
[ dup 1+ mt-wrap calculate-y ]
[ mt-m + mt-wrap new-nth ]
[ nip ] 2tri ;
: (mt-generate) ( n mt-seq -- y to from-elt )
[ >r dup 1+ mt-wrap r> calculate-y ]
[ >r mt-m + mt-wrap r> nth ]
[ drop ] 2tri ;
: mt-generate ( mt -- )
[ seq>> mt-n [ dupd (mt-generate) set-generated ] with each ]
[ >r mt-n r> seq>> [ [ (mt-generate) ] keep set-generated ] curry each ]
[ 0 >>i drop ] bi ;
: init-mt-first ( seed -- seq )
>r mt-n 0 <array> r>
HEX: ffffffff bitand 0 new-set-nth ;
HEX: ffffffff bitand 0 pick set-nth ;
: init-mt-formula ( seq i -- f(seq[i]) )
tuck new-nth dup -30 shift bitxor 1812433253 * +
tuck swap nth dup -30 shift bitxor 1812433253 * +
1+ HEX: ffffffff bitand ;
: init-mt-rest ( seq -- )
mt-n 1- [0,b) [
dupd [ init-mt-formula ] keep 1+ new-set-nth drop
dupd [ init-mt-formula ] keep 1+ rot set-nth
] with each ;
: init-mt-seq ( seed -- seq )
@ -68,7 +70,7 @@ M: mersenne-twister seed-random ( mt seed -- )
init-mt-seq >>seq drop ;
M: mersenne-twister random-32* ( mt -- r )
dup [ seq>> ] [ i>> ] bi
dup mt-n < [ drop 0 pick mt-generate ] unless
new-nth mt-temper
dup [ i>> ] [ seq>> ] bi
over mt-n < [ nip >r dup mt-generate 0 r> ] unless
nth mt-temper
swap [ 1+ ] change-i drop ;