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+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Randomly pick point on the sphere surface.
+#
+# References:
+# [1] Shpere Poin Picking -- from Wolfram MathWorld
+#     http://mathworld.wolfram.com/SpherePointPicking.html
+# [2] Random Points on a Sphere
+#     https://www.jasondavies.com/maps/random-points/
+#
+# Aaron LI
+# 2015/06/18
+
+__version__ = "0.1.0"
+__date__ = "2015/06/16"
+
+import math
+import random
+
+def sphere_point(n=1, unit="rad"):
+    """
+    Randomly uniformly pick a point on the sphere surface.
+    Using the method "Sphere Point Picking" from Wolfram MathWorld.
+
+    Arguments:
+        n: number of points to be generated
+        unit: unit of output values: rad/deg
+
+    Return:
+        (theta, phi): spherical coordinate (unit: rad).
+                      theta: [0, 2\pi); phi: [0 - \pi]
+        If n > 1, then return a list of (theta, phi)
+    """
+    points = []
+    for i in range(n):
+        u = random.random()
+        v = random.random()
+        theta = 2.0 * math.pi * u
+        phi = math.acos(2.0*v - 1.0)
+        if unit == "deg":
+            theta = rad2deg(theta)
+            phi = rad2deg(phi)
+        points.append((theta, phi))
+    if n == 1:
+        return points[0]
+    else:
+        return points
+
+
+def rad2deg(x):
+    return x * 180.0 / math.pi
+
+def deg2rad(x):
+    return x * math.pi / 180.0
+
+