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Diffstat (limited to 'Algorithms/Part-I/5-KdTrees/NearestNeighborVisualizer.java')
-rw-r--r-- | Algorithms/Part-I/5-KdTrees/NearestNeighborVisualizer.java | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/Algorithms/Part-I/5-KdTrees/NearestNeighborVisualizer.java b/Algorithms/Part-I/5-KdTrees/NearestNeighborVisualizer.java new file mode 100644 index 0000000..97cd1e4 --- /dev/null +++ b/Algorithms/Part-I/5-KdTrees/NearestNeighborVisualizer.java @@ -0,0 +1,59 @@ +/************************************************************************* + * Compilation: javac NearestNeighborVisualizer.java + * Execution: java NearestNeighborVisualizer input.txt + * Dependencies: PointSET.java KdTree.java Point2D.java In.java StdDraw.java + * + * Read points from a file (specified as a command-line argument) and + * draw to standard draw. Highlight the closest point to the mouse. + * + * The nearest neighbor according to the brute-force algorithm is drawn + * in red; the nearest neighbor using the kd-tree algorithm is drawn in blue. + * + *************************************************************************/ + +public class NearestNeighborVisualizer { + + public static void main(String[] args) { + String filename = args[0]; + In in = new In(filename); + + StdDraw.show(0); + + // initialize the two data structures with point from standard input + PointSET brute = new PointSET(); + KdTree kdtree = new KdTree(); + while (!in.isEmpty()) { + double x = in.readDouble(); + double y = in.readDouble(); + Point2D p = new Point2D(x, y); + kdtree.insert(p); + brute.insert(p); + } + + while (true) { + + // the location (x, y) of the mouse + double x = StdDraw.mouseX(); + double y = StdDraw.mouseY(); + Point2D query = new Point2D(x, y); + + // draw all of the points + StdDraw.clear(); + StdDraw.setPenColor(StdDraw.BLACK); + StdDraw.setPenRadius(.01); + brute.draw(); + + // draw in red the nearest neighbor (using brute-force algorithm) + StdDraw.setPenRadius(.03); + StdDraw.setPenColor(StdDraw.RED); + brute.nearest(query).draw(); + StdDraw.setPenRadius(.02); + + // draw in blue the nearest neighbor (using kd-tree algorithm) + StdDraw.setPenColor(StdDraw.BLUE); + kdtree.nearest(query).draw(); + StdDraw.show(0); + StdDraw.show(40); + } + } +} |