1 ! Copyright (C) 2004, 2005 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
4 USING: errors kernel math math-internals ;
6 : exp ( x -- y ) >rect swap fexp swap polar> ; inline
7 : log ( x -- y ) >polar swap flog swap rect> ; inline
9 GENERIC: sqrt ( x -- y ) foldable
11 M: complex sqrt >polar swap fsqrt swap 2.0 / polar> ;
14 >float dup 0.0 < [ neg fsqrt 0.0 swap rect> ] [ fsqrt ] if ;
16 GENERIC: (^) ( x y -- z ) foldable
21 [ 2drop 0.0/0.0 ] [ 0 < [ drop 1.0/0.0 ] when ] if
26 : ^mag ( w abs arg -- magnitude )
27 >r >r >float-rect swap r> swap fpow r> rot * fexp /f ;
30 : ^theta ( w abs arg -- theta )
31 >r >r >float-rect r> flog * swap r> * + ; inline
34 swap >polar 3dup ^theta >r ^mag r> polar> ;
38 { [ dup zero? ] [ 2drop 1 ] }
39 { [ dup 1 number= ] [ drop ] }
40 { [ t ] [ over sq over 2 /i ^n -rot 2 mod ^n * ] }
44 dup 0 < [ neg ^n recip ] [ ^n ] if ;
46 : power-of-2? ( n -- ? )
48 dup dup neg bitand number=
55 { [ dup 0 <= ] [ "log2 expects positive inputs" throw ] }
56 { [ dup 1 number= ] [ drop 0 ] }
57 { [ t ] [ -1 shift log2 1+ ] }