Commit: c30a7f5c33c935d863797a46d6bef292f1531eb7 - myprojects-hg-reborn (hg)

Commit MetaInfo

• Revisión: c30a7f5c33c935d863797a46d6bef292f1531eb7 (tree)
• Tiempo: 2016-04-14 18:58:14
• Autor: Lorenzo Isella <lorenzo.isella@gmai...>
• Commiter: Lorenzo Isella

Log Message

A self-contained example about plotting some point in 3D, calculating their convex hull and visualizing them.

Cambiar Resumen

• add: Python-codes/convex-hull-test2.py

Diferencia incremental

diff -r c3c4e58f5691 -r c30a7f5c33c9 Python-codes/convex-hull-test2.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Python-codes/convex-hull-test2.py	Thu Apr 14 11:58:14 2016 +0200
@@ -0,0 +1,61 @@
+#! /usr/bin/env python
+
+
+import numpy as np
+import pylab as pl
+import scipy as sp
+from scipy.spatial import ConvexHull
+from scipy.spatial.distance import euclidean
+import matplotlib.pyplot as plt
+import mpl_toolkits.mplot3d as a3
+
+
+# see http://bit.ly/1qJlWkP
+
+aspect = 0
+while aspect == 0:
+
+    # Generate random points & convex hull
+    points = np.random.rand(20,3)
+    hull = ConvexHull(points)
+
+    # Check aspect ratios of surface facets
+    aspectRatio = []
+    for simplex in hull.simplices:
+        a = euclidean(points[simplex[0],:], points[simplex[1],:])
+        b = euclidean(points[simplex[1],:], points[simplex[2],:])
+        c = euclidean(points[simplex[2],:], points[simplex[0],:])
+        circRad = (a*b*c)/(np.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))
+        inRad = 0.5*np.sqrt(((b+c-a)*(c+a-b)*(a+b-c))/(a+b+c))
+        aspectRatio.append(inRad/circRad)
+
+    # Threshold for minium allowable aspect raio of surface facets
+    if np.amin(aspectRatio) > 0.3:
+        aspect = 1
+
+
+
+        
+ax = a3.Axes3D(pl.figure())
+facetCol = sp.rand(3) #[0.0, 1.0, 0.0]
+
+# Plot hull's vertices
+#for vert in hull.vertices:    
+#    ax.scatter(points[vert,0], points[vert,1], zs=points[vert,2])
+
+# Plot surface traingulation
+for simplex in hull.simplices:
+    vtx = [points[simplex[0],:], points[simplex[1],:], points[simplex[2],:]]
+    tri = a3.art3d.Poly3DCollection([vtx], linewidths = 2, alpha = 0.8)
+    tri.set_color(facetCol)
+    tri.set_edgecolor('k')
+    ax.add_collection3d(tri)
+
+# mp = Axes3D.scatter(points[:,0], points[:,1], point[:,2])
+
+ax.scatter(points[:,0], points[:,1], points[:,2], s=100)
+
+plt.axis('off')
+plt.show()
+
+print "So far so good"