40 lines
952 B
Factor
40 lines
952 B
Factor
! Copyright (C) 2005 Slava Pestov.
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! See http://factor.sf.net/license.txt for BSD license.
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IN: math
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USING: arrays generic kernel sequences ;
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! Vectors
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: vneg ( v -- v ) [ neg ] map ;
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: n*v ( n v -- v ) [ * ] map-with ;
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: v*n ( v n -- v ) swap n*v ;
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: n/v ( n v -- v ) [ / ] map-with ;
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: v/n ( v n -- v ) swap [ swap / ] map-with ;
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: v+ ( v v -- v ) [ + ] 2map ;
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: v- ( v v -- v ) [ - ] 2map ;
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: v* ( v v -- v ) [ * ] 2map ;
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: v/ ( v v -- v ) [ / ] 2map ;
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: vmax ( v v -- v ) [ max ] 2map ;
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: vmin ( v v -- v ) [ min ] 2map ;
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: sum ( v -- n ) 0 [ + ] reduce ;
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: product ( v -- n ) 1 [ * ] reduce ;
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: set-axis ( x y axis -- v )
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2dup v* >r >r drop dup r> v* v- r> v+ ;
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: v. ( v v -- x )
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#! Dot product.
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0 [ * + ] 2reduce ;
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: norm-sq ( v -- n ) 0 [ absq + ] reduce ;
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: norm ( vec -- n )
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#! Length of a vector.
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norm-sq sqrt ;
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: normalize ( vec -- uvec )
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#! Unit vector with same direction as vec.
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dup norm v/n ;
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