21 lines
625 B
Factor
21 lines
625 B
Factor
! Copyright (C) 2008 Doug Coleman.
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! See http://factorcode.org/license.txt for BSD license.
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USING: arrays kernel sequences namespaces make math math.ranges
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math.vectors vectors ;
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IN: math.numerical-integration
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SYMBOL: num-steps 180 num-steps set-global
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: setup-simpson-range ( from to -- frange )
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2dup swap - num-steps get / <range> ;
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: generate-simpson-weights ( seq -- seq )
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{ 1 4 }
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swap length 2 / 2 - { 2 4 } <repetition> concat
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{ 1 } 3append ;
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: integrate-simpson ( from to f -- x )
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[ setup-simpson-range dup ] dip
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map dup generate-simpson-weights
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v. swap [ third ] keep first - 6 / * ;
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