def save_mesh(self, p=2, fname='test.vtu'):
mf = MeshFactory()
mesh = mf.boxmesh2d([0, 1, 0, 1], nx=2, ny=2, meshtype='tri')
node = mesh.entity('node')
cell = mesh.entity('cell')
mesh = LagrangeTriangleMesh(node, cell, p=p)
mesh.to_vtk(fname=fname)
def surface_mesh(self, p=2, fname='surface.vtu'):
from fealpy.geometry import SphereSurface, EllipsoidSurface, SphereSurfaceTest
surface = SphereSurface()
#surface = SphereSurfaceTest()
#surface = EllipsoidSurface()
#surface = ScaledSurface(surface,scale=[9,3,1])
mesh = surface.init_mesh()
node = mesh.entity('node')
cell = mesh.entity('cell')
lmesh = LagrangeTriangleMesh(node, cell, p=p, surface=surface)
NC = lmesh.number_of_cells()
a = lmesh.cell_area()
lmesh.to_vtk(fname=fname)
def interpolation(self, p=2, n=1, fname='surface.vtu'):
from fealpy.geometry import SphereSurface
from fealpy.pde.surface_poisson_model_3d import SphereSinSinSinData
pde = SphereSinSinSinData()
surface = pde.domain()
mesh = pde.init_mesh(n=n)
node = mesh.entity('node')
cell = mesh.entity('cell')
mesh = LagrangeTriangleMesh(node, cell, p=p, surface=surface)
space = ParametricLagrangeFiniteElementSpace(mesh, p=p)
uI = space.interpolation(pde.solution)
mesh.nodedata['uI'] = uI[:]
error0 = space.integralalg.error(pde.solution, uI.value)
error1 = space.integralalg.error(pde.gradient, uI.grad_value)
print(error0, error1)
mesh.to_vtk(fname=fname)
# 封闭曲面，设置其第 0 个插值节点的值为真解值
bc = DirichletBC(space, pde.solution)
A, F = bc.apply(A, F, uh, threshold=np.array([0]))
uh[:] = spsolve(A, F).reshape(-1)
uI = space.interpolation(pde.solution)
errorMatrix[0, i] = space.integralalg.error(pde.solution,
uh.value,
linear=False)
errorMatrix[1, i] = space.integralalg.error(pde.gradient,
uh.grad_value,
linear=False)
errorMatrix[2, i] = space.integralalg.error(pde.solution,
uI.value,
linear=False)
errorMatrix[3, i] = space.integralalg.error(pde.gradient,
uI.grad_value,
linear=False)
if i < maxit - 1:
mesh.uniform_refine()
lmesh.nodedata['uh'] = uh
lmesh.nodedata['uI'] = uI
lmesh.to_vtk(fname='surface_with_solution.vtu')
show_error_table(NDof, errorType, errorMatrix)
showmultirate(plt, 0, NDof, errorMatrix, errorType, propsize=20)
plt.show()
from fealpy.mesh import LagrangeTriangleMesh, MeshFactory, LagrangeWedgeMesh
from fealpy.writer import MeshWriter
#p = int(sys.argv[1])
#n = int(sys.argv[2])
#h = sys.argv[3]
#nh = int(sys.argv[4])
fname = 'initial/file1.vtu'
data = meshio.read(fname)
node = data.points
cell = data.cells[0][1]
mesh = LagrangeTriangleMesh(node*500, cell, p=1)
mesh.uniform_refine(n=0)
mesh = LagrangeWedgeMesh(mesh, h=0.005, nh=1, p=1)
edge = mesh.entity('edge')
node = mesh.entity('node')
cell = mesh.entity('cell')
tface, qface = mesh.entity('face')
print(tface.shape)
mesh.celldata['a'] = np.arange(len(cell))
mesh.to_vtk(fname='write.vtu')