25 lines
638 B
Factor
25 lines
638 B
Factor
|
! Copyright (C) 2009 Samuel Tardieu.
|
||
|
|
! See http://factorcode.org/license.txt for BSD license.
|
||
|
|
USING: kernel math math.functions sequences vectors ;
|
||
|
|
IN: math.continued-fractions
|
||
|
|
|
||
|
|
<PRIVATE
|
||
|
|
|
||
|
|
: split-float ( f -- d i ) dup >integer [ - ] keep ;
|
||
|
|
|
||
|
|
: closest ( seq -- newseq ) unclip-last round >integer suffix ;
|
||
|
|
|
||
|
|
PRIVATE>
|
||
|
|
|
||
|
|
: next-approx ( seq -- )
|
||
|
|
dup [ pop split-float ] [ push ] bi
|
||
|
|
dup zero? [ 2drop ] [ recip swap push ] if ;
|
||
|
|
|
||
|
|
: >ratio ( seq -- a/b )
|
||
|
|
closest reverse unclip-slice [ swap recip + ] reduce ;
|
||
|
|
|
||
|
|
: approx ( epsilon float -- a/b )
|
||
|
|
dup 1vector
|
||
|
|
[ 3dup >ratio - abs < ] [ dup next-approx ] while
|
||
|
|
2nip >ratio ;
|