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#coding=utf8
########################################################################
### ###
### Created by Martin Genet, 2016 ###
### ###
### École Polytechnique, Palaiseau, France ###
### ###
########################################################################
import dolfin
import myVTKPythonLibrary as myVTK
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import myFEniCSPythonLibrary as myFEniCS
########################################################################
def compute_quadrature_degree_from_points_count(
image_filename,
mesh_filebasename,
mesh_ext="vtk",
deg_min=1,
deg_max=20,
verbose=1):
image = myVTK.readImage(
filename=image_filename,
verbose=verbose)
n_points = image.GetNumberOfPoints()
mesh = myVTK.readUGrid(
filename=mesh_filebasename+"."+mesh_ext,
verbose=verbose)
n_cells = mesh.GetNumberOfCells()
(cell_locator,
closest_point,
generic_cell,
k_cell,
subId,
dist) = myVTK.getCellLocator(
mesh=mesh,
verbose=verbose)
point = numpy.empty(3)
n_pixels = numpy.zeros(n_cells)
for k_point in xrange(n_points):
image.GetPoint(k_point, point)
k_cell = cell_locator.FindCell(point)
if (k_cell == -1): continue
else: n_pixels[k_cell] += 1
n_pixels_max = int(max(n_pixels))
n_pixels_avg = int(sum(n_pixels)/n_cells)
if (verbose):
#print "n_pixels = "+str(n_pixels)
#print "sum(n_pixels) = "+str(sum(n_pixels))
print "n_pixels_max = "+str(n_pixels_max)
print "n_pixels_avg = "+str(n_pixels_avg)
mesh = dolfin.Mesh(mesh_filebasename+"."+"xml")
for degree in xrange(deg_min,deg_max+1):
if (verbose): print "degree = "+str(degree)
n_quad = len(dolfin.FunctionSpace(
mesh,
dolfin.FiniteElement(
family="Quadrature",
cell=mesh.ufl_cell(),
degree=degree,
quad_scheme="default")).dofmap().dofs())/len(mesh.cells())
if (verbose): print "n_quad = "+str(n_quad)
#if (n_quad > n_pixels_max): break
if (n_quad > n_pixels_avg): break
return degree
########################################################################
def compute_quadrature_degree_from_integral(
deg_min=1,
deg_max=10,
tol=1e-2,
n_under_tol=1,
verbose=1):
image_dimension = myVTK.computeImageDimensionality(
Martin Genet
committed
image_filename=image_filename,
if (verbose): print "image_dimension = " + str(image_dimension)
dX = dolfin.dx(mesh)
first_time = True
k_under_tol = 0
for degree in xrange(deg_min,deg_max+1):
if (verbose): print "degree = " + str(degree)
fe = dolfin.FiniteElement(
family="Quadrature",
cell=mesh.ufl_cell(),
degree=degree,
quad_scheme="default")
if (image_dimension == 2):
I0 = myFEniCS.ExprIm2(
filename=image_filename,
element=fe)
elif (image_dimension == 3):
I0 = myFEniCS.ExprIm3(
filename=image_filename,
element=fe)
else:
assert (0), "image_dimension must be 2 or 3. Aborting."
if not (first_time):
I0_norm_old = I0_norm
I0_norm = dolfin.assemble(I0**2 * dX, form_compiler_parameters={'quadrature_degree':degree})**(1./2)
if (verbose): print "I0_norm = " + str(I0_norm)
if (first_time):
first_time = False
continue
I0_norm_err = abs(I0_norm-I0_norm_old)/I0_norm_old
if (verbose): print "I0_norm_err = " + str(I0_norm_err)
if (I0_norm_err < tol):
k_under_tol += 1
k_under_tol = 0
if (k_under_tol >= n_under_tol):
break