! See http://factorcode.org/license.txt for BSD license.
! mersenne twister based on
! http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/CODES/mt19937ar.c
-USING: kernel math namespaces sequences sequences.private system
-init accessors math.ranges random math.bitwise combinators
-specialized-arrays.uint fry ;
+USING: alien.c-types alien.data kernel math namespaces sequences
+sequences.private system init accessors math.ranges random
+math.bitwise combinators specialized-arrays fry ;
+SPECIALIZED-ARRAY: uint
IN: random.mersenne-twister
<PRIVATE
TUPLE: mersenne-twister { seq uint-array } { i fixnum } ;
-: mt-n 624 ; inline
-: mt-m 397 ; inline
-: mt-a HEX: 9908b0df ; inline
+CONSTANT: n 624
+CONSTANT: m 397
+CONSTANT: a uint-array{ 0 0x9908b0df }
-: mersenne-wrap ( n -- n' )
- dup mt-n > [ mt-n - ] when ; inline
+: y ( n seq -- y )
+ [ nth-unsafe 31 mask-bit ]
+ [ [ 1 + ] [ nth-unsafe ] bi* 31 bits ] 2bi bitor ; inline
-: wrap-nth ( n seq -- obj )
- [ mersenne-wrap ] dip nth-unsafe ; inline
-
-: set-wrap-nth ( obj n seq -- )
- [ mersenne-wrap ] dip set-nth-unsafe ; inline
-
-: calculate-y ( n seq -- y )
- [ wrap-nth 31 mask-bit ]
- [ [ 1+ ] [ wrap-nth ] bi* 31 bits ] 2bi bitor ; inline
-
-: (mt-generate) ( n seq -- next-mt )
+: mt[k] ( offset n seq -- )
[
- calculate-y
- [ 2/ ] [ odd? mt-a 0 ? ] bi bitxor
- ] [
- [ mt-m + ] [ wrap-nth ] bi*
- ] 2bi bitxor ; inline
+ [ [ + ] dip nth-unsafe ]
+ [ y [ 2/ ] [ 1 bitand a nth ] bi bitxor ] 2bi
+ bitxor
+ ] 2keep set-nth-unsafe ; inline
: mt-generate ( mt -- )
[
- mt-n swap seq>> '[
- _ [ (mt-generate) ] [ set-wrap-nth ] 2bi
- ] each
+ seq>>
+ [ [ n m - ] dip '[ [ m ] dip _ mt[k] ] each-integer ]
+ [ [ m 1 - ] dip '[ [ m n - ] [ n m - + ] bi* _ mt[k] ] each-integer ]
+ bi
] [ 0 >>i drop ] bi ; inline
: init-mt-formula ( i seq -- f(seq[i]) )
- dupd wrap-nth dup -30 shift bitxor 1812433253 * + 1+ 32 bits ; inline
+ dupd nth dup -30 shift bitxor 1812433253 * + 1 + 32 bits ; inline
: init-mt-rest ( seq -- )
- mt-n 1- swap '[
- _ [ init-mt-formula ] [ [ 1+ ] dip set-wrap-nth ] 2bi
- ] each ; inline
+ n 1 - swap '[
+ _ [ init-mt-formula ] [ [ 1 + ] dip set-nth ] 2bi
+ ] each-integer ; inline
: init-mt-seq ( seed -- seq )
- 32 bits mt-n <uint-array>
+ 32 bits n uint <c-array>
[ set-first ] [ init-mt-rest ] [ ] tri ; inline
: mt-temper ( y -- yt )
dup -11 shift bitxor
- dup 7 shift HEX: 9d2c5680 bitand bitxor
- dup 15 shift HEX: efc60000 bitand bitxor
+ dup 7 shift 0x9d2c5680 bitand bitxor
+ dup 15 shift 0xefc60000 bitand bitxor
dup -18 shift bitxor ; inline
: next-index ( mt -- i )
- dup i>> dup mt-n < [ nip ] [ drop mt-generate 0 ] if ; inline
+ dup i>> dup n < [ nip ] [ drop mt-generate 0 ] if ; inline
PRIVATE>
init-mt-seq 0 mersenne-twister boa
dup mt-generate ;
-M: mersenne-twister seed-random ( mt seed -- )
- init-mt-seq >>seq drop ;
+M: mersenne-twister seed-random ( mt seed -- mt' )
+ init-mt-seq >>seq
+ [ mt-generate ]
+ [ 0 >>i drop ]
+ [ ] tri ;
M: mersenne-twister random-32* ( mt -- r )
[ next-index ]
- [ seq>> wrap-nth mt-temper ]
- [ [ 1+ ] change-i drop ] tri ;
+ [ seq>> nth-unsafe mt-temper ]
+ [ [ 1 + ] change-i drop ] tri ;
-USE: init
+: default-mersenne-twister ( -- mersenne-twister )
+ [ 32 random-bits ] with-system-random
+ <mersenne-twister> ;
[
- [ 32 random-bits ] with-system-random
- <mersenne-twister> random-generator set-global
-] "bootstrap.random" add-init-hook
+ default-mersenne-twister random-generator set-global
+] "bootstrap.random" add-startup-hook
+