def init_mesh(self, n=2, meshtype='tet'):
node = np.array([[-1, -1, -1], [1, -1, -1], [1, 1, -1], [-1, 1, -1],
[-1, -1, 1], [1, -1, 1], [1, 1, 1], [-1, 1, 1]],
dtype=np.float64)
cell = np.array([[0, 1, 2, 6], [0, 5, 1, 6], [0, 4, 5, 6],
[0, 7, 4, 6], [0, 3, 7, 6], [0, 2, 3, 6]],
dtype=np.int_)
mesh = TetrahedronMesh(node, cell)
for i in range(n):
mesh.bisect()
NN = mesh.number_of_nodes()
node = mesh.entity('node')
cell = mesh.entity('cell')
bc = mesh.entity_barycenter('cell')
isDelCell = ((bc[:, 0] > 0) & (bc[:, 1] < 0))
cell = cell[~isDelCell]
isValidNode = np.zeros(NN, dtype=np.bool)
isValidNode[cell] = True
node = node[isValidNode]
idxMap = np.zeros(NN, dtype=mesh.itype)
idxMap[isValidNode] = range(isValidNode.sum())
cell = idxMap[cell]
mesh = TetrahedronMesh(node, cell)
mesh.label() # 标记最长边
return mesh
import numpy as np
from fealpy.mesh.TetrahedronMesh import TetrahedronMesh
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
node = np.array([[-1, -1, -1], [1, -1, -1], [1, 1, -1], [-1, 1, -1],
[-1, -1, 1], [1, -1, 1], [1, 1, 1], [-1, 1, 1]],
dtype=np.float)
cell = np.array([[0, 1, 2, 6], [0, 5, 1, 6], [0, 4, 5, 6], [0, 7, 4, 6],
[0, 3, 7, 6], [0, 2, 3, 6]],
dtype=np.int)
mesh = TetrahedronMesh(node, cell)
mesh.bisect()
mesh.bisect()
mesh.bisect()
mesh.bisect()
fig = plt.figure()
axes = fig.gca(projection='3d')
mesh.add_plot(axes, alpha=0, showedge=True)
mesh.find_node(axes)
mesh.find_edge(axes)
mesh.find_cell(axes)
plt.show()