factor/extra/math/extras/extras.factor

154 lines
3.4 KiB
Factor

! Copyright (C) 2012 John Benediktsson
! See http://factorcode.org/license.txt for BSD license
USING: combinators.short-circuit grouping kernel math
math.combinatorics math.constants math.functions math.order
math.primes math.ranges math.statistics math.vectors memoize
sequences ;
IN: math.extras
<PRIVATE
DEFER: sterling
: (sterling) ( n k -- x )
[ [ 1 - ] bi@ sterling ]
[ [ 1 - ] dip sterling ]
[ nip * + ] 2tri ;
PRIVATE>
MEMO: sterling ( n k -- x )
2dup { [ = ] [ nip 1 = ] } 2||
[ 2drop 1 ] [ (sterling) ] if ;
<PRIVATE
DEFER: bernoulli
: (bernoulli) ( p -- n )
[ iota ] [ 1 + ] bi [
0 [ [ nCk ] [ bernoulli * ] bi + ] with reduce
] keep recip neg * ;
PRIVATE>
MEMO: bernoulli ( p -- n )
[ 1 ] [ (bernoulli) ] if-zero ;
: chi2 ( actual expected -- n )
0 [ dup 0 > [ [ - sq ] keep / + ] [ 2drop ] if ] 2reduce ;
<PRIVATE
: df-check ( df -- )
even? [ "odd degrees of freedom" throw ] unless ;
: (chi2P) ( chi/2 df/2 -- p )
[1,b) dupd n/v cum-product swap neg e^ [ v*n sum ] keep + ;
PRIVATE>
: chi2P ( chi df -- p )
dup df-check [ 2.0 / ] [ 2 /i ] bi* (chi2P) 1.0 min ;
<PRIVATE
: check-jacobi ( m -- m )
dup { [ integer? ] [ 0 > ] [ odd? ] } 1&&
[ "modulus must be odd positive integer" throw ] unless ;
: mod' ( x y -- n )
[ mod ] keep over zero? [ drop ] [
2dup [ sgn ] same? [ drop ] [ + ] if
] if ;
PRIVATE>
: jacobi ( a m -- n )
check-jacobi [ mod' ] keep 1
[ pick zero? ] [
[ pick even? ] [
[ 2 / ] 2dip
over 8 mod' { 3 5 } member? [ neg ] when
] while swapd
2over [ 4 mod' 3 = ] both? [ neg ] when
[ [ mod' ] keep ] dip
] until [ nip 1 = ] dip 0 ? ;
<PRIVATE
: check-legendere ( m -- m )
dup prime? [ "modulus must be prime positive integer" throw ] unless ;
PRIVATE>
: legendere ( a m -- n )
check-legendere jacobi ;
: moving-average ( seq n -- newseq )
<clumps> [ mean ] map ;
: exponential-moving-average ( seq a -- newseq )
[ 1 ] 2dip [ [ dupd swap - ] dip * + dup ] curry map nip ;
: moving-median ( u n -- v )
<clumps> [ median ] map ;
: moving-supremum ( u n -- v )
<clumps> [ supremum ] map ;
: moving-infimum ( u n -- v )
<clumps> [ infimum ] map ;
: moving-sum ( u n -- v )
<clumps> [ sum ] map ;
: moving-count ( ... u n quot: ( ... elt -- ... ? ) -- ... v )
[ <clumps> ] [ [ count ] curry map ] bi* ; inline
: nonzero ( seq -- seq' )
[ zero? not ] filter ;
: bartlett ( n -- seq )
dup 1 <= [ 1 = { 1 } { } ? ] [
[ iota ] [ 1 - 2 / ] bi [
[ recip * ] [ >= ] 2bi [ 2 swap - ] when
] curry map
] if ;
: hanning ( n -- seq )
dup 1 <= [ 1 = { 1 } { } ? ] [
[ iota ] [ 1 - 2pi swap / ] bi v*n
[ cos -0.5 * 0.5 + ] map!
] if ;
: hamming ( n -- seq )
dup 1 <= [ 1 = { 1 } { } ? ] [
[ iota ] [ 1 - 2pi swap / ] bi v*n
[ cos -0.46 * 0.54 + ] map!
] if ;
: blackman ( n -- seq )
dup 1 <= [ 1 = { 1 } { } ? ] [
[ iota ] [ 1 - 2pi swap / ] bi v*n
[ [ cos -0.5 * ] map ] [ [ 2 * cos 0.08 * ] map ] bi
v+ 0.42 v+n
] if ;
: nan-sum ( seq -- n )
0 [ dup fp-nan? [ drop ] [ + ] if ] binary-reduce ;
: nan-min ( seq -- n )
[ fp-nan? not ] filter infimum ;
: nan-max ( seq -- n )
[ fp-nan? not ] filter supremum ;
: sinc ( x -- y )
[ 1 ] [ pi * [ sin ] [ / ] bi ] if-zero ;
: until-zero ( n quot -- )
[ dup zero? ] swap until drop ; inline