def f2(p):
x = p[..., 0]
y = p[..., 1]
val = np.exp(5*(x**2 + (y-1)**2))/np.exp(10)
return val
node = np.array([
(0, 0),
(1, 0),
(1, 1),
(0, 1)], dtype=np.float)
cell = np.array([
(1, 2, 0),
(3, 0, 2)], dtype=np.int)
mesh = TriangleMesh(node, cell)
mesh.uniform_refine(4)
node = mesh.entity('node')
cell = mesh.entity('cell')
tmesh = Tritree(node, cell)
femspace = LagrangeFiniteElementSpace(mesh, p=1)
uI = femspace.interpolation(f1)
estimator = Estimator(uI[:], mesh, 0.3, 0.5)
fig = plt.figure()
axes = fig.gca()
mesh.add_plot(axes, cellcolor=estimator.eta, showcolorbar=True)
tmesh.adaptive_refine(estimator)
def refine_tri(self, maxit=2, method='rg', plot=True, rb=True):
cell = np.array([[0, 1, 2], [0, 2, 3], [1, 4, 5], [2, 1, 5]],
dtype=np.int)
node = np.array([[0, 0], [1, 0], [1, 1], [0, 1], [2, 0], [2, 1]],
dtype=np.float)
if False:
mesh = TriangleMesh(node, cell)
mesh = HalfEdgeMesh.from_mesh(mesh)
mesh.ds.cell2hedge = np.array([0, 3, 2, 11, 10])
isMarkedCell = np.array([0, 1, 0, 0, 1], dtype=np.bool_)
#mesh.refine_triangle_rbg(isMarkedCell)
mesh.ds.NV = 3
cell = mesh.ds.cell_to_node()
node = mesh.entity('node')
mesh = TriangleMesh(node, cell)
mesh = HalfEdgeMesh2d.from_mesh(mesh)
mesh.init_level_info()
if False:
fig = plt.figure()
axes = fig.gca()
mesh.add_plot(axes)
mesh.add_halfedge_plot(axes, showindex=True)
mesh.find_node(axes, showindex=True)
mesh.find_cell(axes, showindex=True)
plt.show()
NE = mesh.ds.NE
color = np.zeros(NE * 2, dtype=np.int_)
if method == 'rg':
color[[4, 13, 17, 28]] = 1
color[[23, 27]] = 2
color[[22, 26]] = 3
mesh.hedgecolor = color
isMarkedCell = np.array(
[0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0], dtype=np.bool_)
mesh.refine_triangle_rg(isMarkedCell)
else:
color[[2, 3, 10, 11]] = 1
mesh.hedgecolor = color
isMarkedCell = np.array([0, 1, 1, 0, 0], dtype=np.bool_)
#isMarkedCell = np.array([0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 ,0],
# dtype=np.bool_)
mesh.refine_triangle_nvb(isMarkedCell)
mesh.print()
if plot:
fig = plt.figure()
axes = fig.gca()
mesh.add_plot(axes)
mesh.add_halfedge_plot(axes, showindex=True)
mesh.find_node(axes, showindex=True)
mesh.find_cell(axes, showindex=True)
plt.show()
if True:
mesh = TriangleMesh(node, cell)
mesh = HalfEdgeMesh2d.from_mesh(mesh)
mesh.init_level_info()
NE = mesh.ds.NE
color = np.zeros(NE * 2, dtype=np.int_)
if method == 'nvb':
color[[2, 3, 10, 11]] = 1
mesh.hedgecolor = color
c = np.array([0.8, 0.8])
r = 0.9
h = 1e-2
k = 0
NB = 0
start = time.time()
while k < maxit:
halfedge = mesh.ds.halfedge
halfedge1 = halfedge[:, 3]
node = mesh.node
flag = node - c
flag = flag[:, 0]**2 + flag[:, 1]**2
flag = flag <= r**2
flag1 = flag[halfedge[:, 0]].astype(int)
flag2 = flag[halfedge[halfedge1, 0]].astype(int)
markedge = flag1 + flag2 == 1
markedcell = halfedge[markedge, 1]
markedcell = np.unique(markedcell)
cell = np.unique(halfedge[:, 1])
nc = cell.shape[0]
markedcell1 = np.zeros(nc)
markedcell1[markedcell] = 1
if method == 'rg':
mesh.refine_triangle_rg(markedcell1.astype(np.bool_))
else:
mesh.refine_triangle_nvb(markedcell1.astype(np.bool_))
k += 1
print('循环', k, '次***************************')
end = time.time()
print('用时', end - start)
if plot:
fig = plt.figure()
axes = fig.gca()
nindex = mesh.nodedata['level']
mesh.add_plot(axes)
#mesh.add_halfedge_plot(axes, showindex=True)
#mesh.find_node(axes, showindex=True, multiindex=nindex)
#mesh.find_cell(axes, showindex=True)
#print(np.c_[np.arange(len(mesh.hedgecolor)), mesh.hedgecolor])
plt.show()
def to_mesh(self):
isLeafCell = self.is_leaf_cell()
return TriangleMesh(self.node, self.ds.cell[isLeafCell])
def init_mesh(self, n=3, meshtype='tri'):
node = np.array([(0, 0), (1, 0), (1, 1), (0, 1)], dtype=np.float)
cell = np.array([(1, 2, 0), (3, 0, 2)], dtype=np.int)
mesh = TriangleMesh(node, cell)
mesh.uniform_refine(n)
return mesh
from fealpy.mesh.SurfaceTriangleMeshOptAlg import SurfaceTriangleMeshOptAlg
from fealpy.mesh import TriangleMesh
#surface = Sphere()
surface = HeartSurface()
n = 20
#mesh = iso_surface(surface, surface.box, nx=n, ny=n, nz=n)
ialg = InterfaceMesh3d(surface, surface.box, n)
mesh = ialg.run('interfacemesh')
alg = SurfaceTriangleMeshOptAlg(surface, mesh, gamma=1, theta=0.1)
isNonDelaunayEdge = alg.run(10)
NC = mesh.number_of_cells()
NN = mesh.number_of_nodes()
cell = mesh.entity('cell')
print(NN, cell.max(), cell.min())
node = mesh.entity('node')
edge2cell = mesh.ds.edge_to_cell()
isNonDelaunayCell = np.zeros(NC, dtype=np.bool)
isNonDelaunayCell[edge2cell[isNonDelaunayEdge, 0:2]] = True
mesh0 = TriangleMesh(node, cell[isNonDelaunayCell])
fig = plt.figure()
axes = fig.add_subplot(111, projection='3d')
mesh0.add_plot(axes)
plt.show()
