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