import nmesh large = nmesh.box([-4, -4], [4, 4]) small = nmesh.box([-2, -2], [2, 2]) diff = nmesh.difference(large, [small]) bbox = [[-4, -4], [4, 4]] mesh = nmesh.mesh(bounding_box=bbox, objects=[diff]) nmesh.visual.plot2d_ps(mesh, "fixedpoints_faulty.ps") #can provide some 'fixed points' to avoid round corners fixed_points = [[-2, -2], [2, -2], [-2, 2], [2, 2]] mesh = nmesh.mesh(bounding_box=bbox, objects=[diff], fixed_points=fixed_points) nmesh.visual.plot2d_ps(mesh, "fixedpoints.ps")
# plan. There is a problematic issue with the dof name resolution of
# the EOM LHS! FIXME!
# Notes:
#
# (1) It is somewhat problematic/annoying that the first script does
# not really make clear when a name is a MWE name and when it is a
# field/vector name. Corrected that for this example.
import os, time, sys, math
import nmesh
execfile("../../interface/nsim/linalg_machine.py")
objects = [
nmesh.difference(nmesh.ellipsoid([3.0, 3.0], [("shift", [0, 0])]),
[nmesh.ellipsoid([2.5, 2.5], [("shift", [0, 0])])])
]
mesh = nmesh.mesh(
objects=objects,
a0=0.25,
bounding_box=[[-5.0, -5.0], [5.0, 5.0]],
cache_name="geometry.mesh",
)
raw_mesh = mesh.raw_mesh
if ocaml.petsc_is_mpi():
print "*** PARALLEL EXECUTION ***"
nr_nodes = ocaml.petsc_mpi_nr_nodes()
nr_points = ocaml.mesh_nr_points(raw_mesh)
# A parallelizable demo script implementing a reaction/diffusion system
# ("burning sparkler")
import os,time,sys,math
import nmesh
execfile("../interface/nsim/linalg_machine.py")
objects=[nmesh.difference(nmesh.ellipsoid([3.0,3.0],[("shift",[0,0])]),
[nmesh.ellipsoid([2.5,2.5],[("shift",[0,0])])])
]
mesh = nmesh.mesh(objects=objects,
a0=0.25,
bounding_box=[[-5.0,-5.0],[5.0,5.0]],
cache_name="linalg_machine_rd.mesh",
)
raw_mesh=mesh.raw_mesh
if ocaml.petsc_is_mpi():
print "*** PARALLEL EXECUTION ***"
nr_nodes=ocaml.petsc_mpi_nr_nodes()
nr_points=ocaml.mesh_nr_points(raw_mesh)
z=nr_points/nr_nodes
distrib = [int(round(z*(i+1)))-int(round(z*i)) for i in range(0,nr_nodes)]
slack=nr_points-reduce(lambda x,y:x+y,distrib)
distrib[0] = distrib[0] + slack
print "*** RAW MESH %s *** DISTRIB %s ***" %(repr(raw_mesh),repr(distrib))
ocaml.mesh_set_vertex_distribution(raw_mesh,distrib)
print
"""
** Example: meshing four rings & solving the laplace equation
for a space-dependent resistivity that depends on outer parameters
(Presumably, we will encounter bugs at our first try)
**
"""
##### Creating the mesh #####
# For now, we use a very very simple mesh...
rings = nmesh.union([nmesh.difference(nmesh.ellipsoid([3.0,3.0],
transform=[("shift",[-2.5,0.0])]),
[nmesh.ellipsoid([1.5,1.5],
transform=[("shift",[-2.5,0.0])])]),
nmesh.difference(nmesh.ellipsoid([3.0,3.0],
transform=[("shift",[2.5,0.0])]),
[nmesh.ellipsoid([1.5,1.5],
transform=[("shift",[2.5,0.0])])])])
boxed_rings=nmesh.intersect([rings,nmesh.box([-8.0,-2.5],[8.0,2.5])])
N = 100
density = "density=1.;"
the_mesh = nmesh.mesh(objects = [boxed_rings],
cache_name="rings-mesh",
a0=0.3,
bounding_box=[[-10.0,-3.5],[10.0,3.5]],
nfem.set_default_dimension(2)
nfem.set_default_order(1)
# Simulation parameters
sigma0 = 1.0
print
"""
** Example: meshing half ring and compute current density for contacts at either side.
This is for possible collaboration with Uni Hamburg. **
"""
##### Creating the mesh #####
ring = nmesh.difference(
nmesh.ellipsoid([4.0, 4.0]), [nmesh.ellipsoid([2.5, 2.5])])
halfring = nmesh.intersect([ring, nmesh.box([-4.0, -0.0], [4.0, 4.0])])
the_mesh = nmesh.mesh(
objects=[halfring],
cache_name="halfring",
a0=0.2,
bounding_box=[[-4.0, -4], [4.0, 4.0]],
neigh_force_scale=1.,
initial_settling_steps=50,
max_relaxation=4,
max_steps=400)
nfem.set_default_mesh(the_mesh)
for x in range(-1,2):
for y in range(-1,2):
# external ring
R = nmesh.ellipsoid(
[outer_radius, outer_radius],
transform=[("shift",[x*centres_distance, y*centres_distance])]
)
#internal ring
r = nmesh.ellipsoid(
[inner_radius, inner_radius],
transform=[("shift",[x*centres_distance, y*centres_distance])]
)
# take the difference
rings.append(nmesh.difference(R,[r]))
# cut the rings at top and bottom
union_rings = nmesh.union(rings)
rings_array = nmesh.intersect([union_rings,rings_box])
# semiaxis of a rhombus on the diagonals of the array
d = (centres_distance/2.) - Numeric.sqrt(outer_radius**2 - (centres_distance/2.)**2)
# rhombi on the diagonals of the array
for x in range(-3,4,2):
for y in range(-3,4,2):
centre_x = 0.5*x*centres_distance
centre_y = 0.5*y*centres_distance
print
"""
** Example: meshing four rings & solving the laplace equation
for a space-dependent resistivity that depends on outer parameters
(Presumably, we will encounter bugs at our first try)
**
"""
##### Creating the mesh #####
# For now, we use a very very simple mesh...
rings = nmesh.union([
nmesh.difference(
nmesh.ellipsoid([3.0, 3.0], transform=[("shift", [-2.5, 0.0])]),
[nmesh.ellipsoid([1.0, 1.0], transform=[("shift", [-2.5, 0.0])])]),
nmesh.difference(
nmesh.ellipsoid([3.0, 3.0], transform=[("shift", [2.5, 0.0])]),
[nmesh.ellipsoid([1.0, 1.0], transform=[("shift", [2.5, 0.0])])])
])
boxed_rings = nmesh.intersect([rings, nmesh.box([-8.0, -2.5], [8.0, 2.5])])
N = 100
density = "density=1.;"
the_mesh = nmesh.mesh(
objects=[boxed_rings],
cache_name="rings-mesh",
a0=0.508,
"""
** Example: meshing four rings & solving the laplace equation
for a space-dependent resistivity that depends on outer parameters
(Presumably, we will encounter bugs at our first try)
**
"""
##### Creating the mesh #####
# For now, we use a very very simple mesh...
rings = nmesh.union(
[
nmesh.difference(
nmesh.ellipsoid([3.0, 3.0], transform=[("shift", [-2.5, 0.0])]),
[nmesh.ellipsoid([1.0, 1.0], transform=[("shift", [-2.5, 0.0])])],
),
nmesh.difference(
nmesh.ellipsoid([3.0, 3.0], transform=[("shift", [2.5, 0.0])]),
[nmesh.ellipsoid([1.0, 1.0], transform=[("shift", [2.5, 0.0])])],
),
]
)
boxed_rings = nmesh.intersect([rings, nmesh.box([-8.0, -2.5], [8.0, 2.5])])
N = 100
density = "density=1.;"
the_mesh = nmesh.mesh(
objects=[boxed_rings],
for x in range(-1,2):
for y in range(-1,2):
# external ring
R = nmesh.ellipsoid(
[outer_radius, outer_radius],
transform=[("shift",[x*centres_distance, y*centres_distance])]
)
#internal ring
r = nmesh.ellipsoid(
[inner_radius, inner_radius],
transform=[("shift",[x*centres_distance, y*centres_distance])]
)
# take the difference
rings.append(nmesh.difference(R,[r]))
# cut the rings at top and bottom
union_rings = nmesh.union(rings)
rings_array = nmesh.intersect([union_rings,rings_box])
# semiaxis of a rhombus on the diagonals of the array
d = (centres_distance/2.) - Numeric.sqrt(outer_radius**2 - (centres_distance/2.)**2)
# rhombi on the diagonals of the array
for x in range(-3,4,2):
for y in range(-3,4,2):
centre_x = 0.5*x*centres_distance
centre_y = 0.5*y*centres_distance
import nmesh large = nmesh.box( [-4,-4], [4,4] ) small = nmesh.box( [-2,-2], [2,2] ) diff = nmesh.difference(large,[small]) bbox=[[-4,-4],[4,4]] mesh = nmesh.mesh(bounding_box=bbox, objects = [diff] ) nmesh.visual.plot2d_ps( mesh, "fixedpoints_faulty.ps") #can provide some 'fixed points' to avoid round corners fixed_points = [[-2,-2],[2,-2],[-2,2],[2,2]] mesh = nmesh.mesh(bounding_box=bbox, objects = [diff], fixed_points=fixed_points ) nmesh.visual.plot2d_ps( mesh, "fixedpoints.ps")
nfem.set_default_dimension(2)
nfem.set_default_order(1)
# Simulation parameters
sigma0=1.0
print
"""
** Example: meshing half ring and compute current density for contacts at either side.
This is for possible collaboration with Uni Hamburg. **
"""
##### Creating the mesh #####
ring = nmesh.difference(nmesh.ellipsoid([4.0,4.0]),[nmesh.ellipsoid([2.5,2.5])])
halfring=nmesh.intersect([ring,nmesh.box([-4.0,-0.0],[4.0,4.0])])
the_mesh = nmesh.mesh(objects = [halfring],
cache_name="halfring",
a0=0.2,
bounding_box=[[-4.0,-4],[4.0,4.0]],
neigh_force_scale = 1.,
initial_settling_steps = 50,
max_relaxation = 4,
max_steps=400
)
nfem.set_default_mesh(the_mesh)
import nmesh big = nmesh.ellipsoid([4.0,3.0]) # create a big ellipsoid small = nmesh.ellipsoid([3.0,2.0]) # small ellipsoid diff = nmesh.difference(big,[small])# create difference of ellipsoids bbox = [[-5.,-4.],[5.,4.]] mesh_ex = nmesh.mesh(objects = [diff], a0=0.4, bounding_box=bbox) # plot mesh nmesh.visual.plot2d_ps(mesh_ex,"difference.ps")
bbox = [[-10,-10,-thickness/2.],[10,10,thickness/2.]]
trasl = [0,5.,0]
# external ring
R = nmesh.conic(
[0.0,0.0,-thickness], outer_radius, [0.0,0.0,thickness], outer_radius, \
transform=[("shift",trasl)]
)
#internal ring
r = nmesh.conic(
[0.0,0.0,-thickness], inner_radius, [0.0,0.0,thickness], inner_radius, \
transform=[("shift",trasl)],
)
# take the difference
ring = nmesh.difference(R,[r])
box = nmesh.box([-10,0,-thickness/2.],[10,10,thickness/2.])
system = nmesh.intersect([ring, box])
density = """density = 1.;"""
N = 50
# create mesh of three objects and bounding box
mesh_ex = nmesh.mesh(objects = [system],
a0=rod,
bounding_box=bbox,
density = density,
import nmesh big = nmesh.ellipsoid([4.0, 3.0]) # create a big ellipsoid small = nmesh.ellipsoid([3.0, 2.0]) # small ellipsoid diff = nmesh.difference(big, [small]) # create difference of ellipsoids bbox = [[-5., -4.], [5., 4.]] mesh_ex = nmesh.mesh(objects=[diff], a0=0.4, bounding_box=bbox) # plot mesh nmesh.visual.plot2d_ps(mesh_ex, "difference.ps")