script/tutorial/65_ConvexHull.js

@@ -0,0 +1,70 @@
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// Example of convex hull plot
+//
+//////////////////////////////////////////////////////////////////////////////////////////////////
+
+
+function add_convex_hull_plot(title, x,y, name, clear){
+	if (!is_defined(name))    name = null
+	if (!is_defined(clear))    clear = false
+    plots = get_plots(title = title)
+    p = null
+    if (plots.length==0){
+        p = plot(null,name=name, undefined, undefined, title = title)[0]        
+        p.getAxis(AxisId.X).setRange(-50,150)
+        p.getAxis(AxisId.Y).setRange(-50,150)
+        p.setLegendVisible(true)      
+    } else {
+        p = plots[0]    
+        if (clear){
+            p.clear()
+        }
+        p.addSeries(new LinePlotSeries(name))            
+    }
+    s = p.getSeries(name)        
+    s.setLinesVisible(false)
+    s.setPointSize(3)
+    s.setData(x, y)         
+
+    //In the first time the plot shows, it takes some time for the color to be assigned
+    while (s.color == null){
+        sleep(0.001)
+    }        
+
+    hull = new LinePlotSeries(name + " Hull", s.color)
+        
+    //Bounding box
+    //x1 = Math.min.apply(null, x) 
+    //x2 = Math.max.apply(null, x) 
+    //y1 = Math.min.apply(null, y) 
+    //y2 = Math.max.apply(null, y) 
+    //(hx,hy) = ([x1,x2, x2, x1, x1], [y1, y1, y2, y2, y1])     
+    
+    //Convex Hull
+    ret = convex_hull(point_list=undefined, x=x, y=y)
+    hx=ret[0]
+    hy=ret[1]
+    hx.push(hx[0])
+    hy.push(hy[0])
+                
+    p.addSeries(hull)                   
+    hull.setLineWidth(2)
+    hull.setData(hx,hy)     
+    hull.setColor(s.color)    
+}    
+        
+title = "Convex Hull"
+if (get_plots(title).length>0){
+    get_plots(title)[0].clear()
+}    
+
+for (var step=1; step<=5; step++){
+    x=[]
+    y=[]
+    for (var i=0; i<=50 ; i++){
+        x.push(Math.random() * 100 / step)
+        y.push(Math.random() * 100/ step)        
+    }
+    add_convex_hull_plot (title, x,y,"Scan " + step)
+}    
+