First version of the script to draw the solutions

scripts/draw_solution.sage

@@ -0,0 +1,81 @@
+FIGURE_SIZE = 10
+POINT_SIZE = FIGURE_SIZE
+
+def turn_direction(a,b,c):
+    x1,x2,x3=a[0],b[0],c[0]
+    y1,y2,y3=a[1],b[1],c[1]
+    return (x2-x1)*(y3-y1)-(y2-y1)*(x3-x1)
+
+def angle_distance(dx,dy):
+    dx,dy = n(dx), n(dy)
+    length = sqrt(dx*dx+dy*dy)
+    return (dx / length, -length)
+
+def chull_2d(points):
+    """Computes the convex hull of a set of 2-dimensional points."""
+
+    points = copy(points)
+
+    # Find the point with lower y-coordinate
+    pivot = min(points, key=(lambda x: (x[1],x[0])))
+    points.remove(pivot)
+
+    # Sorts all the points according to the angle
+    points.sort(key=(lambda p : angle_distance(p[0]-pivot[0],p[1]-pivot[1])), reverse=True)
+
+    # Add the two first points to the stack
+    stack = [pivot,points[0]]
+
+    k = 1
+    while k < len(points):
+        p0 = stack[len(stack)-2]
+        p1 = stack[len(stack)-1]
+        p2 = points[k]
+
+        t = turn_direction(p0,p1,p2)
+        
+        # Left turn or straight
+        if(t <= 0):
+            stack.pop()
+
+        # Right turn or straight
+        if(t >= 0):
+            stack.append(p2)
+            k = k+1
+
+    return stack
+
+# data file
+(node_count, cluster_count) = [ int(x) for x in raw_input().split(' ') ]
+
+all_points = []
+points = []
+for i in range(cluster_count):
+    points.append([])
+
+for i in range(node_count):
+    (x,y,cluster) = [ int(float(x)) for x in raw_input().split(' ') ]
+    points[cluster].append((x,y))
+    all_points.append((x,y))
+
+# solutions file
+edges_count = int(raw_input())
+edges = []
+for i in range(edges_count):
+    edges.append([int(x) for x in raw_input().split(' ') ])
+
+
+plot = list_plot([], xmax=100, xmin=0, ymax=100, ymin=0)
+
+for i in range(cluster_count):
+    plot = plot + list_plot(points[i], color='gray', figsize=FIGURE_SIZE,
+            pointsize=POINT_SIZE)
+
+    if(len(points[i]) > 1):
+        vertices = chull_2d(list(set(points[i])))
+        plot = plot + sum([line([vertices[k],vertices[(k+1)%len(vertices)]],
+                thickness=POINT_SIZE/20, color='gray') for k in range(len(vertices))])
+
+plot = plot + sum([line([all_points[edges[k][0]], all_points[edges[k][1]]]) for k in range(edges_count)])
+
+save(plot, "tmp/gtsp.png")