Question

上面的代码目前生成一个立方体，而不是一个球体。我怎么能纠正这个？

x = list(range(-5,5))
y = list(range(-5,5))
z = list(range(-5,5))
r = [1,2,3,4,5,6,7,10]
xcoords = []
ycoords = []
zcoords = []
"""functions used"""
def square(number):
return number**2
"""determines which values satisfies the equation for a sphere"""
for itemx in x:
    for itemy in y:
        for itemz in z:
            for itemr in r:
                if abs(itemx) == abs(itemy) and abs(itemy) == abs(itemz) and square(itemx) + square(itemy) +square(itemz) == itemr:
                xcoords.append(itemx)
                ycoords.append(itemy)
                zcoords.append(itemz)
"""determines the number of atoms in the system"""
natoms = len(xcoords)
"""writes coords onto txt file"""
out = open("sphere.xyz", "a")
print (natoms)
out.write("%s \n \n" %(natoms))
out.close()
for item in zip(xcoords, ycoords,zcoords):
   out = open("sphere.xyz", "a")
   print (item)
   out.write( "Ar"  " " " " "%2.5s %2.5s %2.5s \n" %(item))
   out.close()

我考虑使用球面坐标来定义球体的参数，但我不知道如何使用python进行设置。

Answer 1

正如我在评论中提到的，我认为你是误解情况的受害者。我的方法会有所不同 - 不要迭代固定数量的坐标并尝试点击，但只生成正确的点。我使用了众所周知的球形到笛卡尔公式，并且只为这两个角度生成了固定样本。

from __future__ import division
from math import sin, cos, pi

SAMPLES = 20

def to_x(r, theta, phi):
    return r*sin(theta)*cos(phi)

def to_y(r, theta, phi):
    return r*sin(theta)*sin(phi)

def to_z(r, theta, phi):
    return r*cos(theta)

samples_r = [r for r in xrange(1, 10)]
samples_theta = [theta * pi / SAMPLES for theta in xrange(SAMPLES)]
samples_phi = [phi * 2*pi / SAMPLES for phi in xrange(SAMPLES)]

coords = []

for r in samples_r:
    for theta in samples_theta:
        for phi in samples_phi:
            coords.append((to_x(r, theta, phi), 
                           to_y(r, theta, phi),
                           to_z(r, theta, phi)))

for coord in coords:
   out = open("sphere.xyz", "a")
   print (coord)
   out.write( "Ar"  " " " " "%2.5s %2.5s %2.5s \n" %(coord))
   out.close()

为了提高内存性能，您可以考虑使用generators和itertools模块（尤其是itertools.product似乎是针对类似问题设计的。）

如何使用python获取球体的坐标？

1 个答案: