Voronoi diagram/J/Delaunay triangulation: Difference between revisions

Voronoi diagram/J/Delaunay triangulation (view source)

28 bytes added , 12 years ago

m

Bug in convex_hull repaired. Occurred when more than 1 point have smallest y value.

Anonymous user

Revision as of 18:27, 1 February 2012 (view source) rosettacode>Mwn3d m (moved DelaunayVoronoiInJ to Voronoi diagram/J/Delaunay triangulation: Naming convention) ← Older edit		Revision as of 04:15, 2 February 2012 (view source) rosettacode>Lambertdw m (Bug in convex_hull repaired. Occurred when more than 1 point have smallest y value.) Newer edit →
Line 137: crossproduct=: 1 \|. ([ * 1 \|. ]) - ] * 1 \|. [ NB. j forum wind=: {:@:crossproduct&(,&0) NB. positive if CCL smallest_by_coordinate=: 4 : '(#~ (= <./)@:(x&{"1)) y' convex_hull=: 3 : 0 NB. Graham Scan y are the points y=. ~. y NB. Implements Robert Sedgewick pseudo-code N=. # y start=. <, > smallest_by_coordinate&.>/ 0 ; 1 ; y ~~if. start -.@:e. y do. start=. start ,@:(=&({:"1) # ]) y end.~~ y=. y -. start y=. y ([ /: angle@:-"1) start