1 ! Copyright (C) 2008 John Benediktsson, Doug Coleman.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: grouping kernel math math.statistics math.vectors
7 : sma ( seq n -- newseq )
12 : weighted ( prev elt a -- newelt )
13 [ 1 swap - * ] [ * ] bi-curry bi* + ; inline
20 : ema ( seq n -- newseq )
21 [ cut [ mean dup ] dip ] [ a ] bi
22 [ weighted dup ] curry map nip swap prefix ;
24 : dema ( seq n -- newseq )
25 [ ema ] keep [ drop 2 v*n ] [ ema ] 2bi
26 [ length tail* ] keep v- ;
28 : gdema ( seq n v -- newseq )
29 [ [ ema ] keep dupd ema ] dip
30 [ 1 + v*n ] [ v*n ] bi-curry bi*
31 [ length tail* ] keep v- ;
33 : tema ( seq n -- newseq )
34 [ ema ] keep dupd [ ema ] keep
35 [ drop [ 3 v*n ] bi@ [ length tail* ] keep v- ] [ ema nip ] 3bi
36 [ length tail* ] keep v+ ;
38 : macd ( seq n1 n2 -- newseq )
39 rot dup ema [ swap ema ] dip v- ;
41 : momentum ( seq n -- newseq )
42 [ tail-slice ] 2keep [ dup length ] dip - head-slice v- ;
44 : performance ( seq -- newseq )
45 dup first '[ _ [ - ] [ /f ] bi 100 * ] map ;
47 : monthly ( x -- y ) 12 / ; inline
49 : semimonthly ( x -- y ) 24 / ; inline
51 : biweekly ( x -- y ) 26 / ; inline
53 : weekly ( x -- y ) 52 / ; inline
55 : daily-360 ( x -- y ) 360 / ; inline
57 : daily-365 ( x -- y ) 365 / ; inline