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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
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