def init_mesh(self, n=0, p=None):
t = self.CircleCurve.radius
c = np.sqrt(3.0) / 2.0
node = np.array(
[[0.0, 0.0], [t, 0.0], [t / 2.0, c * t], [-t / 2.0, c * t],
[-t, 0.0], [-t / 2.0, -c * t], [t / 2.0, -c * t]],
dtype=np.float64)
cell = np.array(
[[0, 1, 2], [0, 2, 3], [0, 3, 4], [0, 4, 5], [0, 5, 6], [0, 6, 1]],
dtype=np.int_)
mesh = TriangleMesh(node, cell)
for i in range(n):
NN = mesh.number_of_nodes()
mesh.uniform_refine()
node = mesh.entity('node')
self.CircleCurve.project(node[NN:])
node = mesh.entity('node')
cell = mesh.entity('cell')
mesh = LagrangeTriangleMesh(node, cell, p=p)
isBdNode = mesh.ds.boundary_node_flag()
node = mesh.entity('node')
bdnode = node[isBdNode]
self.CircleCurve.project(bdnode)
node[isBdNode] = bdnode
return mesh
def customized_mesh(self):
# box = self.box
# mesh = MF.boxmesh2d(box, nx=10, ny=20, meshtype='tri')
# mesh = HalfEdgeMesh2d.from_mesh(mesh, NV=3) # 三角形网格的单边数据结构
cell = np.array(
[[0, 1, 3], [4, 3, 1], [4, 1, 5], [2, 5, 1], [6, 3, 7], [4, 7, 3],
[4, 5, 7], [8, 7, 5], [6, 7, 9], [10, 9, 7], [10, 7, 11],
[8, 11, 7], [12, 9, 13], [10, 13, 9], [10, 11, 13], [14, 13, 11]],
dtype=np.int)
node = np.array([[0, -1], [0.5, -1], [1, -1], [0, -0.5], [0.5, -0.5],
[1, -0.5], [0, 0], [0.5, 0], [1, 0], [0, 0.5],
[0.5, 0.5], [1, 0.5], [0, 1], [0.5, 1], [1, 1]],
dtype=np.float)
mesh = TriangleMesh(node, cell)
mesh = HalfEdgeMesh2d.from_mesh(mesh, NV=3)
mesh.uniform_refine(2)
cm = 1.
tt = 0.2
while cm > 0.01 / 2:
bc = mesh.cell_barycenter()
NC = mesh.number_of_cells()
cellstart = mesh.ds.cellstart
isMarkedCell = np.zeros(NC + cellstart, dtype=np.bool_)
isMarkedCell[cellstart:] = abs(bc[:, 1] - 0.) < tt
mesh.refine_triangle_rg(isMarkedCell)
cm = np.sqrt(np.min(mesh.entity_measure('cell')))
if tt > 0.025:
tt = tt / 2.
# |--- 下面做一下网格结构的转换, 因为目前 HalfEdgeMesh2d 对 p>1 时有 bug
mesh = TriangleMesh(mesh.node, mesh.entity('cell'))
return mesh
def space_mesh(self, n=4):
point = np.array([(0, 0), (2, 0), (4, 0), (0, 2), (2, 2), (4, 2)],
dtype=np.float)
cell = np.array([(3, 0, 4), (1, 4, 0), (2, 5, 1), (4, 1, 5)],
dtype=np.int)
mesh = TriangleMesh(point, cell)
mesh.uniform_refine(n)
return mesh
def lshape_mesh(r=1):
point = np.array([(-1, -1), (0, -1), (-1, 0), (0, 0), (1, 0), (-1, 1),
(0, 1), (1, 1)],
dtype=np.float)
cell = np.array([(0, 1, 3, 2), (2, 3, 6, 5), (3, 4, 7, 6)], dtype=np.int)
tmesh = TriangleMesh(point, cell)
if r > 0:
tmesh.uniform_refine(r)
return tmesh
def init_mesh(self, n=4, meshtype='tri'):
node = np.array([(-1, -1), (0, -1), (1, -1), (-1, 0), (0, 0), (1, 0),
(-1, 1), (0, 1), (1, 1)],
dtype=np.float)
if meshtype is 'tri':
cell = np.array([(1, 4, 0), (3, 0, 4), (4, 1, 5), (2, 5, 1),
(4, 7, 3), (6, 3, 7), (7, 4, 8), (5, 8, 4)],
dtype=np.int)
mesh = TriangleMesh(node, cell)
mesh.uniform_refine(n)
elif meshtype is 'quadtree':
cell = np.array([(0, 1, 4, 3), (1, 2, 5, 4), (3, 4, 7, 6),
(4, 5, 8, 7)],
dtype=np.int)
mesh = Quadtree(node, cell)
mesh.uniform_refine(n)
else:
raise ValueError("".format)
return mesh
def init_mesh(self, n=4, meshtype='tri'):
node = np.array([(-1, -1), (0, -1), (-1, 0), (0, 0), (1, 0), (-1, 1),
(0, 1), (1, 1)],
dtype=np.float64)
if meshtype == 'tri':
cell = np.array([(1, 3, 0), (2, 0, 3), (3, 6, 2), (5, 2, 6),
(4, 7, 3), (6, 3, 7)],
dtype=np.int_)
mesh = TriangleMesh(node, cell)
mesh.uniform_refine(n)
return mesh
elif meshtype == 'quadtree':
cell = np.array([(0, 1, 3, 2), (2, 3, 6, 5), (3, 4, 7, 6)],
dtype=np.int_)
mesh = Quadtree(node, cell)
mesh.uniform_refine(n)
return mesh
elif meshtype == 'tritree':
cell = np.array([(1, 3, 0), (2, 0, 3), (3, 6, 2), (5, 2, 6),
(4, 7, 3), (6, 3, 7)],
dtype=np.int_)
mesh = TriangleMesh(node, cell)
mesh.uniform_refine(n)
node = mesh.entity('node')
cell = mesh.entity('cell')
mesh = Tritree(node, cell)
return mesh
else:
raise ValueError("I don't know the meshtype %s".format(meshtype))
def init_mesh(self, n=1, meshtype='tri'):
node = np.array([(0, 0), (1, 0), (1, 1), (0, 1)], dtype=np.float)
if meshtype is 'tri':
cell = np.array([(1, 2, 0), (3, 0, 2)], dtype=np.int)
mesh = TriangleMesh(node, cell)
mesh.uniform_refine(n)
return mesh
elif meshtype is 'quadtree':
cell = np.array([(0, 1, 2, 3)], dtype=np.int)
mesh = Quadtree(node, cell)
mesh.uniform_refine(n)
return mesh
elif meshtype is 'tritree':
cell = np.array([(1, 2, 0), (3, 0, 2)], dtype=np.int)
mesh = Tritree(node, cell)
mesh.uniform_refine(n)
return mesh
else:
raise ValueError("I don't know the meshtype %s".format(meshtype))
def init_mesh(self, n=4, meshtype='tri'):
if meshtype == 'tri':
node = np.array([(0, -1), (-1, 0), (0, 0), (1, 0), (1, 0), (0, 1)],
dtype=np.float64)
cell = np.array([(2, 1, 0), (2, 0, 3), (2, 5, 1), (2, 4, 5)],
dtype=np.int_)
mesh = TriangleMesh(node, cell)
mesh.uniform_refine(n)
return mesh
elif meshtype == 'quadtree':
r = 1 - 2**(1 / 2) / 2
a = 1 / 2 - 2**(1 / 2) / 2
rr = 1 / 2
node = np.array([(0, -1), (-rr, -rr), (rr, -rr), (-r, -r), (0, -r),
(r, -r), (-1, 0), (-r, 0), (0, 0), (r, 0), (1, 0),
(r, 0), (-r, r), (0, r), (r, r), (-rr, rr),
(rr, rr), (0, 1)],
dtype=np.float64)
cell = np.array([(0, 4, 3, 1), (2, 5, 4, 0), (1, 3, 7, 6),
(3, 4, 8, 7), (4, 5, 9, 8), (5, 2, 10, 9),
(6, 7, 12, 15), (7, 8, 13, 12), (8, 11, 14, 13),
(11, 10, 16, 14), (12, 13, 17, 15),
(13, 14, 16, 17)],
dtype=np.int_)
mesh = Quadtree(node, cell)
mesh.uniform_refine(n)
return mesh
elif meshtype == 'tritree':
node = np.array([(0, -1), (-1, 0), (0, 0), (1, 0), (1, 0), (0, 1)],
dtype=np.float64)
cell = np.array([(2, 1, 0), (2, 0, 3), (2, 5, 1), (2, 4, 5)],
dtype=np.int_)
mesh = Tritree(node, cell)
mesh.uniform_refine(n)
return mesh
else:
raise ValueError("I don't know the meshtype %s".format(meshtype))
verts3 = np.array([
[0.004, 0.025],
[0.004, 0.035]
])
segs3 = np.array([[0, 1]], dtype=np.int32)
m3= np.array([[4]])
verts = np.concatenate([verts0, verts1, verts2, verts3], axis=0)
segs = np.concatenate([segs0, segs1+4, segs2+8, segs3+12], axis=0)
marker = np.concatenate([m0, m1, m2, m3], axis=0)
plsg = {'segments':segs, 'vertices':verts, 'segment_markers':marker}
t = triangle.triangulate(plsg, 'pq30a0.000004')
tmesh = TriangleMesh(t['vertices'], t['triangles'])
tmesh.uniform_refine()
data = {
'node':tmesh.point,
'elem':tmesh.ds.cell + 1,
'node_marker': t['vertex_markers']
}
sio.matlab.savemat('trimesh', data)
#plot.plot(plt.axes(), **t)
#plt.show()
fig = plt.figure()
axes = fig.gca()
tmesh.add_plot(axes)
plt.show()
from fealpy.mesh.TriangleMesh import TriangleMesh
from fealpy.mesh.Tritree import Tritree
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(1)
node = mesh.entity('node')
cell = mesh.entity('cell')
tmesh = Tritree(node, cell)
isLeafCell = tmesh.is_leaf_cell()
flag = (np.sum(cell == 0, axis=1) == 5) & isLeafCell
idx, = np.where(flag)
for i in range(2):
tmesh.refine(idx)
tmesh.coarsen(idx)
fig = plt.figure()
axes = fig.gca()
tmesh.add_plot(axes)
#tmesh.find_node(axes, showindex=True)
#tmesh.find_edge(axes, showindex=True)
#tmesh.find_cell(axes, showindex=True)
def f2(m):
x = m[..., 0]
y = m[..., 1]
val = np.zeros(m.shape, dtype=np.float)
val[..., 0] = 3 * np.exp(x**2 + y**2)
val[..., 1] = 3 * np.exp(x**2 + y**2)
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)
p = 0
mesh = TriangleMesh(node, cell)
mesh.uniform_refine()
node = mesh.entity('node')
cell = mesh.entity('cell')
NC = mesh.number_of_cells()
bc = mesh.entity_barycenter('cell')
if p == 0:
integrator = mesh.integrator(1)
else:
integrator = mesh.integrator(p + 2)
cellmeasure = mesh.entity_measure('cell')
V = VectorLagrangeFiniteElementSpace(mesh, p, spacetype='D')
b = V.source_vector(f2, integrator, cellmeasure)
c = V.scalarspace.source_vector(f1, integrator, cellmeasure)
from fealpy.mesh.mesh_tools import find_entity
import matplotlib.pyplot as plt
# init settings
n = 1 # refine times
p = 2 # polynomial order of FEM space
# q = p + 1 # integration order
q = 2 + 1 # integration order
node = np.array([(0, 0), (1, 0), (1, 1), (0, 1)], dtype=np.float)
# ---- tri mesh ----
cell = np.array([(1, 2, 0), (3, 0, 2)], dtype=np.int) # tri mesh
mesh = TriangleMesh(node, cell)
mesh.uniform_refine(n)
# ------------------
# # ---- quad mesh ----
# cell = np.array([(0, 1, 2, 3)], dtype=np.int) # quad mesh
# # mesh = Quadtree(node, cell)
# mesh = QuadrangleMesh(node, cell)
# mesh.uniform_refine(n)
# # -------------------
fig = plt.figure()
axes = fig.gca()
mesh.add_plot(axes, cellcolor='w')
find_entity(axes,
mesh,
entity='cell',
import numpy as np
import matplotlib.pyplot as plt
from fealpy.mesh.TriangleMesh import TriangleMesh
from fealpy.mesh.Tritree import Tritree
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(0)
node = mesh.entity('node')
cell = mesh.entity('cell')
fig = plt.figure()
axes = fig.gca()
mesh.add_plot(axes)
#mesh.find_node(axes, showindex=True)
#mesh.find_edge(axes, showindex=True)
#mesh.find_cell(axes, showindex=True)
tmesh = Tritree(node, cell)
ismarkedcell = np.array([True, False])
tmesh.refine(ismarkedcell)
fig = plt.figure()
axes = fig.gca()
tmesh.add_plot(axes)
pmesh = tmesh.to_conformmesh()
fig = plt.figure()
axes = fig.gca()
