绘制球形帽

Question

使用Python，我想绘制一个球体在一种颜色和球体上的数量为spherical caps。上限由中心点（角度phi,theta）和半径给出。

这是不可能的，也许MayaVi？

Answer 1

使用matplotlib：

def plot_spherical_cap(ax, b, opening_angle, radius=1.0): 
    r = elevation 
    phi = numpy.linspace(0, 2 * numpy.pi, 30) 
    theta = numpy.linspace(0, opening_angle, 20) 
    X = r * numpy.stack([ 
     numpy.outer(numpy.cos(phi), numpy.sin(theta)), 
     numpy.outer(numpy.sin(phi), numpy.sin(theta)), 
     numpy.outer(numpy.ones(numpy.size(phi)), numpy.cos(theta)), 
     ], axis=-1) 

    # rotate X such that [0, 0, 1] gets rotated to `c`; 
    # <https://math.stackexchange.com/a/476311/36678>. 
    a = numpy.array([0.0, 0.0, 1.0]) 
    a_x_b = numpy.cross(a, b) 
    a_dot_b = numpy.dot(a, b) 
    if a_dot_b == -1.0: 
     X_rot = -X 
    else: 
     X_rot = (
      X + 
      numpy.cross(a_x_b, X) + 
      numpy.cross(a_x_b, numpy.cross(a_x_b, X))/(1.0 + a_dot_b) 
      ) 

    ax.plot_surface(
      X_rot[..., 0], X_rot[..., 1], X_rot[..., 2], 
      rstride=3, cstride=3, 
      color='#1f77b4', 
      alpha=0.5, 
      linewidth=0 
      ) 
    return