def create_mesh():
nx = 3 #how many ellipsoids in x direction
x0 = 3. #spacing of ellipsoids in x
ny = 3 #how many ellipsoids in y direction
y0 = 3. #spacing of ellipsoids in x
nz = 3 #how many ellipsoids in y direction
z0 = 3. #spacing of ellipsoids in x
rx,ry,rz = 0.8,1.2,1#radii of ellipsoids
#create list 'objects' with ellipsoids
objects = []
for i in range(nx):
for j in range(ny):
for k in range(nz):
objects.append( nmesh.ellipsoid([rx,ry,rz], [("shift",[i*x0,j*y0,k*z0])]))
#bounding box
bbox = [[-2,-2,-2],[(nx-1)*x0+2,(ny-1)*y0+2,(nz-1)*z0+2]]
#create the mesh
mesh = nmesh.mesh(objects=objects,a0=0.75,bounding_box=bbox,mesh_bounding_box=True)
#save plot to file
mesh.save("test.nmesh",directory='.')
return mesh
def create_mesh():
nx = 3 #how many ellipsoids in x direction
x0 = 3. #spacing of ellipsoids in x
ny = 3 #how many ellipsoids in y direction
y0 = 3. #spacing of ellipsoids in x
nz = 3 #how many ellipsoids in y direction
z0 = 3. #spacing of ellipsoids in x
rx, ry, rz = 0.8, 1.2, 1 #radii of ellipsoids
#create list 'objects' with ellipsoids
objects = []
for i in range(nx):
for j in range(ny):
for k in range(nz):
objects.append(
nmesh.ellipsoid([rx, ry, rz],
[("shift", [i * x0, j * y0, k * z0])]))
#bounding box
bbox = [[-2, -2, -2],
[(nx - 1) * x0 + 2, (ny - 1) * y0 + 2, (nz - 1) * z0 + 2]]
#create the mesh
mesh = nmesh.mesh(objects=objects,
a0=0.75,
bounding_box=bbox,
mesh_bounding_box=True)
#save plot to file
mesh.save("test.nmesh", directory='.')
return mesh
import nfem, nmesh, math, sys
nfem.set_default_dimension(3)
nfem.set_default_order(1)
bar = nmesh.box([-5.0, -2.0, -2.0], [5.0, 2.0, 2.0])
the_mesh = nmesh.mesh(
objects=[bar],
cache_name="bar-mesh3",
a0=0.7,
bounding_box=[[-6.0, -3.0, -3.0], [6.0, 3.0, 3.0]],
neigh_force_scale=1.,
# density = density,
initial_settling_steps=50,
max_relaxation=4,
# callback=(my_function, N),
# max_steps=677
max_steps=500)
nfem.set_default_mesh(the_mesh)
element_M = nfem.make_element("M", [3])
element_H = nfem.make_element("H", [3])
mwe_M = nfem.make_mwe("mwe_M", [(1, element_M)])
mwe_H = nfem.make_mwe("mwe_H", [(1, element_H)])
diffop_v_laplace = nfem.diffop("-<d/dxj H(k) || d/dxj M(k)>, j:3, k:3")
stack6 = []
iteration = [1000]
#mesh object at different maximum number of iterations N
for N in iteration:
timing.start()
mesh = nmesh.mesh(objects=[box, ellipsoid], bounding_box=bbox,\
a0=0.3, mesh_bounding_box=True,
fixed_points = fix,
#tolerated_rel_move = 0.0009,
max_steps = N,
density = density,
neigh_force_scale = neigh_force,
shape_force_scale = shape_force,
volume_force_scale = 0.0
)
timing.finish()
time.append(timing.seconds())
# save mesh
mesh.save("edge_shape_%d.nmesh" % e)
# load mesh from file
import nmesh ell = nmesh.ellipsoid([3,2]) # create ellipsoid cone = nmesh.conic([-3,0],2,[3,0],0) # create cone inters = nmesh.intersect([ell, cone]) # create intersection of objects bbox = [[-5.,-4.],[5.,4.]] mesh_ex = nmesh.mesh(objects = [inters], a0=0.4, bounding_box=bbox) nmesh.visual.plot2d_ps(mesh_ex,"intersection.ps")
import nmesh
# create a number of objects
one = nmesh.ellipsoid([3.0,3.0])
two = nmesh.ellipsoid([3.0,3.0],transform=[("shift",[7,0])])
three=nmesh.box( [-4.0,-6], [10,-4] )
bbox = [[-5.,-8.],[11.,5.]]
# create mesh of three objects and bounding box
mesh_ex = nmesh.mesh(objects = [one,two,three], bounding_box=bbox,
mesh_bounding_box=True)
# plot mesh
nmesh.visual.plot2d_ps(mesh_ex,"multiobjects.ps")
"""This script demonstrates the function 'separate_parts()' compounded with
'outer_skin()'.
In the first dataset displayed a triangle and square are present. In the
second dataset the square has been removed.
Author: James Kenny Last modified: $Date$
"""
import nmesh
import nmesh.visual as viz
# define a simple mesh and submit request to mesher
box=nmesh.box( [0.0,0.0], [1.0,1.0] )
cone = nmesh.conic([3.0,0.0],1.0,[3.0,4.0],0.0)
bbox = [[-1.,-1.],[7.,6.]]
mesh = nmesh.mesh(objects = [box,cone],a0=0.4, bounding_box=bbox)
mesh_info=mesh.tolists()
# create mesh_info lists for parts 1&2 combined and for part 2 alone
[mesh_info1, mesh_info2] = viz.separate_parts(mesh_info, listOfParts=[[1,2],[2]])
# generate a VTK dataset for parts 1&2 combined
vtkData, points, simplices,indices, icradii, ccradii = \
viz.mesh2vtk(mesh_info1, VTKonly=False)
in2circ=viz.findRatios(icradii, ccradii, factor=2)
vtkData=viz.append2vtk(vtkData, in2circ, "in2circ")
vtkData=viz.append2vtk(vtkData, indices, "part indices")
# 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)
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)
"""
** 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)
the_mesh.save("themesh.nmesh")
# conductivity (scalar)
element_sigma = nfem.make_element("sigma",[]);
element_drho_by_dt= nfem.make_element("drho_by_dt",[]);
element_phi = nfem.make_element("phi",[]);
element_J = nfem.make_element("J",[2]);
import nmesh
box = nmesh.box([0.0,0.0], [1.0,1.0], \
transform=[("rotate2d",45), \
("shift",[-1.0,-2.0]), \
("scale",[1.5,1.5])])
# create ellipsoid
ell = nmesh.ellipsoid([1.0,2.0], \
transform=[("rotate2d",45), \
("shift",[1.0,1.0]),])
rod = 0.5
bbox = [[-3., -3.], [4., 4.]]
# create mesh
mesh = nmesh.mesh(objects=[box, ell], a0=rod, bounding_box=bbox)
# plot mesh
nmesh.visual.plot2d_ps(mesh, "transformations.ps")
# Using the discretized differential operator machinery
# from within python...
#
# NOTE: Mesher (version from 30-04-2007) has difficulty here, cannot
# generate the mesh. Reverting to the mesher version from 01-04-2007 works.
import nmag2 as nmag, nmesh as nm, sys, math, time
import nfem
import nfem.visual
mesh_obj = nm.mesh(([-6.0,-6.0,-6.0],[6.0,6.0,6.0]), # bounding box
objects= [nm.conic([0.0,0.0,-4.0],2.0,[0.0,0.0,4.0],2.0),
nm.conic([0.0,0.0,-5.0],2.0,[0.0,0.0,-4.0],2.0),
nm.conic([0.0,0.0,5.0],2.0,[0.0,0.0,4.0],2.0)
],
a0=0.6,
max_steps=100,
cache_name="ddiffop_mesh_rod")
the_mesh = mesh_obj.raw_mesh
print "MESH: ",the_mesh,type(the_mesh)
elem_scalar = ocaml.make_element("S",[],3,1)
elem_vector = ocaml.make_element("V",[3],3,1)
mwe_scalar=ocaml.make_mwe("mwe_S",the_mesh,[(1,elem_scalar),(2,elem_scalar),(3,elem_scalar)],[])
mwe_vector=ocaml.make_mwe("mwe_V",the_mesh,[(1,elem_vector),(2,elem_vector),(3,elem_vector)],[])
simply_points = [
[0., 0., 0.],
[0., 0., 1.],
[0., 1., 0.],
[0., 1., 1.],
[1., 0., 0.],
[1., 0., 1.],
[1., 1., 0.],
[1., 1., 1.],
[0.4, 1.0, 0.5],
[1., 0., 0.],
[1., 0., 1.],
[1., 1., 0.],
[1., 1., 1.],
[2., 0., 0.],
[2., 0., 1.],
[2., 1., 0.],
[2., 1., 1.],
[1.6, 1.0, 0.5],
]
bbox = [[0.0, 0.0, 0.0], [2.0, 1.0, 1.0]]
mesh = nmesh.mesh(objects=[cube2, cube1],
bounding_box=bbox,
a0=0.6,
simply_points=simply_points)
mesh.save("test-broken-mesh.nmesh")
The user should see that when the outer-box is meshed the triangle
part comprises an additional 'surface element' which should not
actually be there.
Author: James Kenny Last modified: $Date$
"""
import nmesh
import nmesh.visual as viz
# define a simple mesh and submit request to mesher (include outer box)
box = nmesh.box([0.0, 0.0], [1.0, 1.0])
cone = nmesh.conic([3.0, 0.0], 1.0, [3.0, 4.0], 0.0)
bbox = [[-2., -2.], [7., 6.]]
rod = 0.4
mesh = nmesh.mesh(objects=[box, cone],
a0=rod,
bounding_box=bbox,
mesh_bounding_box=True)
mesh_info = mesh.tolists()
# visualise in MayaVi, using the ratio of 2*inradius:circumradius
# as cell_data for a colour scale
mesh_info = viz.surface_only(mesh_info)
vtkData = viz.mesh2vtk(mesh_info)
viz.save_vtk(vtkData, "outerbox_bug_1.vtk")
########### NOW DO THE SAME, BUT WITHOUT THE OUTER BOX ################
# define a simple mesh and submit request to mesher
box = nmesh.box([0.0, 0.0], [1.0, 1.0])
cone = nmesh.conic([3.0, 0.0], 1.0, [3.0, 4.0], 0.0)
bbox = [[-2., -2.], [7., 6.]]
import nmesh # create square box = nmesh.box([0.0,0.0],[1.0,1.0]) # create cone cone = nmesh.conic([3.0,0.0],1.0,[3.0,4.0],0.0) rod= 0.4 bbox = [[-1.,-1.],[7.,6.]] # create mesh and save it in a file every 50 steps # during its construction; with the show flag it # is possible also to visualise it. mesh_ex = nmesh.mesh(objects = [box,cone], a0=rod, bounding_box=bbox) #visualisation missing # plot mesh nmesh.visual.plot2d_ps(mesh_ex,"visual_timeseries2d_mesh.ps")
import nmesh a=2.3 P1 = [0,0,0] #one corner of box P2 = [a,a,a]#other corner box = nmesh.box( P1,P2, use_fixed_corner_points=True) bbox = [[0,0,0],[a,a,a]] mesh = nmesh.mesh(bounding_box=bbox, objects=[box]) mv=nmesh.visual.show_bodies_mayavi( mesh ) nmesh.visual.export_visualisation(mv,'box_with_fixed_corner_points.eps')
import nmesh
box1 = nmesh.box([0.0, 0.0], [3.0, 3.0])
box2 = nmesh.box([-1.0, -1.0], [-3.0, -3.0])
circle = nmesh.ellipsoid(length=[1.5, 1.5], transform=[("shift", [-2., 2.])])
bbox = [[-4, -4], [4, 4]]
#define call back function
def my_fun(piece_nr, iteration_nr, mesh_info):
print "** In callback function: Piece %d, Step %d \n" % \
(piece_nr, iteration_nr)
print "Points = %d\nSimplices = %d\nSurface elements = %d\n" % \
(len(mesh_info[0][2]),len(mesh_info[2][2]),len(mesh_info[4][2]))
#Call callback function every 5 iterations
mesh = nmesh.mesh(objects = [box1,box2,circle], bounding_box=bbox, \
a0=0.5, callback = (my_fun,5))
nmesh.visual.plot2d_ps(mesh, "callback.ps")
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")
import nmesh
nx = 2 #how many ellipsoids in x direction
x0 = 3. #spacing of ellipsoids in x
ny = 3 #how many ellipsoids in y direction
y0 = 3. #spacing of ellipsoids in x
rx,ry = 1,1.5 #radii of ellipsoids
angle = 45 #orientation of ellipsoids
#create list 'objects' with ellipsoids
objects = []
for i in range(nx):
for j in range(ny):
objects.append( nmesh.ellipsoid([rx,ry], \
[("rotate2d",angle),\
("shift",[i*x0,j*y0])]))
#bounding box
bbox = [[-2,-2],[(nx-1)*x0+2,(ny-1)*y0+2]]
#create the mesh
mesh = nmesh.mesh(objects=objects,a0=0.5,bounding_box=bbox)
#Create post script plot of mesh
nmesh.visual.plot2d_ps(mesh,"ellipsoid_array.ps")
#save plot to file
mesh.save('ellipsoid_array.nmesh')
# For now, we use a very very simple mesh...
double_disc_2d = nmesh.union([nmesh.ellipsoid([3.0,3.0], transform=[("shift",[-1.0,0.0])]),
nmesh.ellipsoid([3.0,3.0], transform=[("shift",[1.0,0.0])])])
double_disc_3d = nmesh.union([nmesh.conic([-1.0,0.0,thickness2d*0.5],3.0,[-1.0,0.0,-thickness2d*0.5],3.0),
nmesh.conic([ 1.0,0.0,thickness2d*0.5],3.0,[ 1.0,0.0,-thickness2d*0.5],3.0)])
density = "density=1.;"
mesh_2d = nmesh.mesh(objects = [double_disc_2d],
cache_name="double-disc-2d",
a0=0.4,
bounding_box=[[-5.0,-5.0],[5.0,5.0]],
neigh_force_scale = 1.,
density = density,
initial_settling_steps = 50,
max_relaxation = 4,
max_steps=500
)
mesh_3d = nmesh.mesh(objects = [double_disc_3d],
cache_name="double-disc-3d",
a0=0.4,
bounding_box=[[-5.0,-5.0,-0.3],[5.0,5.0,0.3]],
neigh_force_scale = 1.,
density = density,
initial_settling_steps = 50,
max_relaxation = 4,
max_steps=500
)
# the following two commands save images from pylab and MayaVi
# MayaVi captures the screen to do this, so ensure there are no
# windows on top of MayaVi. (hence the unattended mode should be
# set up to savefig() but not to draw()
pylab.draw()
raw_input()
C_bottom = [0,0,0] #center of spiral
R_spiral = 3 #radius of spiral
C_top = [0,0,10] #top of spiral
R_circle = 3 #radius of max circle along the spiral
helix = nmesh.helix( C_bottom, R_spiral, C_top, R_circle )
bbox = [[-7,-7,-1],[7,7,11]]
N = 5
rod = 0.5
# create mesh of three objects and bounding box
mesh_ex = nmesh.mesh(objects = [helix],
a0=rod,
bounding_box=bbox,
#callback= (my_function,N),
max_steps=1000
)
mesh_ex.save("helix.nmesh")
bbox = [[-1.25,-0.75],[1.25,0.75]]
#Define all parameters, for example in string:
myconf = """
[nmesh-2D]
a0 : 1.0
shape_force_scale : 0.1
volume_force_scale : 0.0
neigh_force_scale : 1.0
irrel_elem_force_scale : 0.0
thresh_add : 0.6
thresh_del : 1.6
initial_settling_steps : 200
sliver_correction : 1.0
max_relaxation : 3.0
topology_threshold : 0.2
max_relaxation : 3.0
topology_threshold : 0.2
time_step_scale : 0.1
tolerated_rel_move : 0.002
max_steps : 2000
"""
#Then create MeshingParameters object
mp = nmesh.MeshingParameters(string=myconf)
#and use MeshingParameter object when computing the mesh:
mesh = nmesh.mesh(objects = [ellipsoid], bounding_box=bbox,a0=0.5,\
meshing_parameters=mp)
import nmesh ell = nmesh.ellipsoid([3, 2]) # create ellipsoid cone = nmesh.conic([-3, 0], 2, [3, 0], 0) # create cone inters = nmesh.intersect([ell, cone]) # create intersection of objects bbox = [[-5., -4.], [5., 4.]] mesh_ex = nmesh.mesh(objects=[inters], a0=0.4, bounding_box=bbox) nmesh.visual.plot2d_ps(mesh_ex, "intersection.ps")
import nmesh, Numeric
rod = 10.
edge = 100
import math
bbox = [[-edge, -edge], [edge, edge]]
# box
box = nmesh.box([-edge, -edge], [edge, edge])
density = """density = 1.;"""
N = 10
# create mesh of three objects and bounding box
mesh_ex = nmesh.mesh(
objects=[box],
a0=rod,
bounding_box=bbox,
density=density,
)
mesh_ex.save("test-demag-2d.nmesh")
# 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)
import nmesh
# rotation of the object is performed
# around the [0,0,1] axis (z-axis).
box = nmesh.box([0, 0, 0], [2, 1, 1], transform=[("rotate", [0, 1], 0)])
bbox = [[-1, -1, -1], [3, 3, 3]]
mesh = nmesh.mesh(objects=[box],
bounding_box=bbox,
mesh_bounding_box=False,
a0=0.5)
mesh.save('rotate.nmesh')
#create 3d-plot of surfaces and export eps
vis = nmesh.visual.show_bodies_mayavi(mesh)
nmesh.visual.export_visualisation(vis, "rotate.eps")
import nmesh
squares = []
for i in range(4):
xshift = i * 6
yshift = 0
squares.append(
nmesh.box([-2, -2], [2, 2], transform=[("shift", [xshift, yshift])]))
bbox = [[-5, -5], [23, 5]]
mesh = nmesh.mesh(objects=squares, bounding_box=bbox)
# plot mesh
nmesh.visual.plot2d_ps(mesh, "shift.ps")
x, y = node
for i in range(nr_layers+1):
layer_heigth = -thickness/2. + layer_thick*i
mobile_pts.append([x, y, layer_heigth])
bbox = [[-edge,-edge,-thickness/2.],[edge,edge,thickness/2.]]
# box
box = nmesh.box([-edge,-edge,-thickness/2.],[edge,edge,thickness/2.])
density = """density = 1.;"""
# create mesh of three objects and bounding box
mesh_ex = nmesh.mesh(objects = [box],
cache_name = "",
a0=rod,
mobile_points = mobile_pts,
bounding_box=bbox,
density = density,
neigh_force_scale = 0.0,
shape_force_scale = 0.0,
max_steps = 1
)
mesh_ex.save("box-2d-to-3d.nmesh")
import nfem, nmesh, math, sys
nfem.set_default_dimension(3)
nfem.set_default_order(1)
bar = nmesh.box([-5.0,-2.0,-2.0],[5.0,2.0,2.0])
the_mesh = nmesh.mesh(objects = [bar],
cache_name="bar-mesh3",
a0=0.7,
bounding_box=[[-6.0,-3.0,-3.0],[6.0,3.0,3.0]],
neigh_force_scale = 1.,
# density = density,
initial_settling_steps = 50,
max_relaxation = 4,
# callback=(my_function, N),
# max_steps=677
max_steps=500
)
nfem.set_default_mesh(the_mesh)
element_M = nfem.make_element("M",[3])
element_H = nfem.make_element("H",[3])
mwe_M = nfem.make_mwe("mwe_M", [(1,element_M)])
mwe_H = nfem.make_mwe("mwe_H", [(1,element_H)])
diffop_v_laplace = nfem.diffop("-<d/dxj H(k) || d/dxj M(k)>, j:3, k:3")
## pylab.plot([px],[py],"bo",markersize = 10)
## print p
##pylab.show()
##raw_input()
N = 100
# create mesh of three objects and bounding box
mesh_ex = nmesh.mesh(objects = [rings_array],#[outer,voltage_probes[0], voltage_probes[1], rings_array],
a0=rod,
bounding_box=bbox,
fixed_points = fix_pts,
neigh_force_scale = 1.,
shape_force_scale = 0.1,
density = density,
thresh_del = 1.4,
initial_settling_steps = 100,
max_relaxation = 4,
#callback=(my_function, N),
max_steps=1000
)
#mesh_loaded = nmesh.load("9rings_alone.nmesh")
mesh_ex.save("9rings.nmesh")
nmesh.visual.plot2d_ps(mesh_ex,"9rings.ps")
import nmesh
ellipsoid = nmesh.ellipsoid([0.75,1.25,1])
# create mesh
bbox = [[-0.75,-1.25,-1],[0.75,1.25,1]]
mesh = nmesh.mesh(objects = [ellipsoid], bounding_box=bbox,a0=0.5)
#create 3d-plot of surfaces and export eps
vis = nmesh.visual.show_bodies_mayavi(mesh)
nmesh.visual.export_visualisation(vis,"simple3d.eps")
#save mesh also as nmesh file
mesh.save('simple3d.nmesh')
import nmesh
ellipse = nmesh.ellipsoid([1])
bbox = [[-2],[2]]
mesh = nmesh.mesh(objects = [ellipse], bounding_box=bbox, a0 = 0.5,
mesh_bounding_box=True)
mesh.save("simple1d.nmesh")
nfem.set_default_dimension(3)
nfem.set_default_order(1)
##### Creating the mesh #####
# For now, we use a very very simple mesh...
ball = nmesh.ellipsoid([3.0,3.0,3.0])
density = "density=1.;"
the_mesh = nmesh.mesh(objects = [ball],
cache_name="bem-ball",
a0=1.0,
bounding_box=[[-5.0,-5.0,-5.0],[5.0,5.0,5.0]],
neigh_force_scale = 1.,
density = density,
initial_settling_steps = 50,
max_relaxation = 4,
max_steps=500
)
nfem.set_default_mesh(the_mesh)
##### Making the elements... #####
element_M = nfem.make_element("M",[3]);
element_H = nfem.make_element("H",[3]);
element_rho_M = nfem.make_element("rho_M",[]);
element_phi_M = nfem.make_element("phi_M",[]);
mwe_M = nfem.make_mwe("mwe_M", [(1,element_M)])
#
# Using the discretized differential operator machinery
# from within python...
#
# NOTE: Mesher (version from 30-04-2007) has difficulty here, cannot
# generate the mesh. Reverting to the mesher version from 01-04-2007 works.
import nmag2 as nmag, nmesh as nm, sys, math, time
import nfem
import nfem.visual
mesh_obj = nm.mesh(
([-6.0, -6.0, -6.0], [6.0, 6.0, 6.0]), # bounding box
objects=[
nm.conic([0.0, 0.0, -4.0], 2.0, [0.0, 0.0, 4.0], 2.0),
],
a0=0.8,
max_steps=400,
cache_name="ddiffop4_mesh_rod")
the_mesh = mesh_obj.raw_mesh
print "MESH: ", the_mesh, type(the_mesh)
elem_scalar = ocaml.make_element("S", [], 3, 1)
elem_vector = ocaml.make_element("V", [3], 3, 1)
def surface_type(pos):
if pos[2] < -3.99:
return -2
# temporarily commented out by turning this into a string...
"""
the_mesh = nm.mesh(([-5.0,-5.0,-5.0],[5.0,5.0,5.0]), # bounding box
objects= \
[nm.difference( \
nm.intersect([nm.conic([0.0,0.0,-2.0],7.0,
[0.0,0.0,2.0],7.0),
nm.box([-4.0,-4.0,-4.0],[4.0,4.0,4.0])]))],
a0=1.2,
max_steps=500,
cache_name="ddiffop_mesh")
"""
mesh_obj = nm.mesh(([-5.0,-5.0,-5.0],[5.0,5.0,5.0]), # bounding box
objects= [nm.conic([0.0,0.0,-2.0],4.0,[0.0,0.0,2.0],4.0)],
a0=1.2,
max_steps=500,
cache_name="ddiffop_mesh")
the_mesh = mesh_obj.raw_mesh
print "MESH: ",the_mesh,type(the_mesh)
elem_T = ocaml.make_element("T",[],3,1)
elem_sigma = ocaml.make_element("sigma",[],3,1)
elem_j_q = ocaml.make_element("j_q",[3],3,1)
mwe_T=ocaml.make_mwe("mwe_T",the_mesh,[(1,elem_T)],[])
mwe_sigma=ocaml.make_mwe("mwe_sigma",the_mesh,[(1,elem_sigma)],[])
mwe_j_q=ocaml.make_mwe("mwe_j_q",the_mesh,[(1,elem_j_q)],[])
** 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)
the_mesh.save("themesh.nmesh")
# conductivity (scalar)
element_sigma = nfem.make_element("sigma", [])
element_drho_by_dt = nfem.make_element("drho_by_dt", [])
element_phi = nfem.make_element("phi", [])
element_J = nfem.make_element("J", [2])
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]],
neigh_force_scale = 1.,
density = density,
initial_settling_steps = 50,
max_relaxation = 4,
# callback=(my_function, N),
# max_steps=677
max_steps=200
)
nfem.set_default_mesh(the_mesh)
##### Making the elements... #####
empty_element=ocaml.empty_element;
# conductivity (scalar)
element_sigma = nfem.make_element("sigma",[]);
element_drho_by_dt= nfem.make_element("drho_by_dt",[]);
import nmesh cigar = nmesh.ellipsoid( [4,2] ) bbox = [[-5,-5],[5,5]] mesh = nmesh.mesh(objects=[cigar], bounding_box=bbox, a0=0.5, mesh_bounding_box=True) nmesh.visual.plot2d_ps( mesh, "tutorial3.ps")
nx = 3 #how many ellipsoids in x direction
x0 = 3. #spacing of ellipsoids in x
ny = 3 #how many ellipsoids in y direction
y0 = 3. #spacing of ellipsoids in x
nz = 3 #how many ellipsoids in y direction
z0 = 3. #spacing of ellipsoids in x
rx, ry, rz = 0.8, 1.2, 1 #radii of ellipsoids
#create list 'objects' with ellipsoids
objects = []
for i in range(nx):
for j in range(ny):
for k in range(nz):
objects.append(
nmesh.ellipsoid([rx, ry, rz],
[("shift", [i * x0, j * y0, k * z0])]))
#bounding box
bbox = [[-2, -2, -2], [(nx - 1) * x0 + 2, (ny - 1) * y0 + 2,
(nz - 1) * z0 + 2]]
#create the mesh
mesh = nmesh.mesh(objects=objects, a0=0.75, bounding_box=bbox)
#save plot to file
mesh.save("ellipsoid_array3d.nmesh")
#create 3d-plot of surfaces and export eps
vis = nmesh.visual.show_bodies_mayavi(mesh)
nmesh.visual.export_visualisation(vis, "ellipsoid_array3d.eps")
# MayaVi captures the screen to do this, so ensure there are no
# windows on top of MayaVi. (hence the unattended mode should be
# set up to savefig() but not to draw()
pylab.draw()
# pylab.savefig('hist_'+str( globals()['call_counter']).zfill(4)+'.png')
nmesh.visual.export_visualisation(globals()['v'],'mesh_'+str( globals()['call_counter']).zfill(4)+'.png')
# increment the call counter
globals()['call_counter'] += 1
# to run attended, comment in the following 2 lines
# create the mesh and visualise it every n steps
N = 1000
mesh = nmesh.mesh(objects = [box,cone], a0=rod, bounding_box=bbox, callback=(my_function, N))
# show the finished mesh
mesh_info = mesh.tolists()
# to do this by writing to disk, uncomment the following 2 lines
globals()['v'], in2circ = nmesh.visual.solid_in2circ(mesh_info, myv=globals()['v'])
globals()['v'].renwin.z_plus_view()
# if we have written to disk first (ie the above line is being used)
# then we can save the VTK file by uncommenting the following line
shutil.copy('in2circ_solid.vtk', 'mesh_'+str(globals()['call_counter']).zfill(4)+'.vtk')
# save an image from MayaVi of the finished mesh
nmesh.visual.export_visualisation(globals()['v'],'mesh_'+str(call_counter).zfill(4)+'.png')
stack5=[]
stack6=[]
iteration = [1,5,10,50,200,500,1000,2000]
#mesh object at different maximum number of iterations N
for N in iteration:
timing.start()
mesh = nmesh.mesh(objects=[box, ellipsoid], bounding_box=bbox,\
a0=0.3, mesh_bounding_box=True,
fixed_points = fix,
max_steps = N,
density = density,
neigh_force_scale = 0.0,
shape_force_scale = shape_elem,
volume_force_scale = 0.0
)
timing.finish()
time.append(timing.seconds())
#iteration.append(N)
#save the mesh as a .ps file in temp dir
nmesh.visual.plot2d_ps(mesh,"fig_mesh_shape_%d_iter%06d.ps"\
% (shape_elem,N) )
nr_layers = 1
layer_thick = thickness / float(nr_layers)
for node in coord_nodes:
x, y = node
for i in range(nr_layers + 1):
layer_heigth = -thickness / 2. + layer_thick * i
mobile_pts.append([x, y, layer_heigth])
bbox = [[-edge, -edge, -thickness / 2.], [edge, edge, thickness / 2.]]
# box
box = nmesh.box([-edge, -edge, -thickness / 2.], [edge, edge, thickness / 2.])
density = """density = 1.;"""
# create mesh of three objects and bounding box
mesh_ex = nmesh.mesh(objects=[box],
cache_name="",
a0=rod,
mobile_points=mobile_pts,
bounding_box=bbox,
density=density,
neigh_force_scale=0.0,
shape_force_scale=0.0,
max_steps=1)
mesh_ex.save("box-2d-to-3d.nmesh")
# the following two commands save images from pylab and MayaVi
# MayaVi captures the screen to do this, so ensure there are no
# windows on top of MayaVi. (hence the unattended mode should be
# set up to savefig() but not to draw()
pylab.draw()
raw_input()
C_bottom = [0, 0, 0] #center of spiral
R_spiral = 3 #radius of spiral
C_top = [0, 0, 10] #top of spiral
R_circle = 3 #radius of max circle along the spiral
helix = nmesh.helix(C_bottom, R_spiral, C_top, R_circle)
bbox = [[-7, -7, -1], [7, 7, 11]]
N = 5
rod = 0.5
# create mesh of three objects and bounding box
mesh_ex = nmesh.mesh(
objects=[helix],
a0=rod,
bounding_box=bbox,
#callback= (my_function,N),
max_steps=1000)
mesh_ex.save("helix.nmesh")
density = """density = 1.;"""
f = open("run_9rings/9rings-small4.nmesh")
data = f.readlines()
f.close()
mob_pts = []
offset = 2
nr_mob_pts = int(data[offset])
for i in range(nr_mob_pts):
x,y = data[offset+1+i].split()
fx, fy = float(x), float(y)
## if i == 5210 or i ==8193:
## print fx, fy
## print "************* pass ************"
## else:
mob_pts.append([fx, fy])
mesh_ex = nmesh.mesh(objects = [rings_array],
a0=rod,
bounding_box=bbox,
mobile_points = mob_pts,
shape_force_scale = 0.0,
neigh_force_scale = 0.0,
max_steps=1
)
mesh_ex.save("aaa.nmesh")
nmesh.visual.plot2d_ps(mesh_ex,"aaa.ps")
import nmesh
box1 = nmesh.box( [-1,-1,2],[1,1,4], \
transform=[("rotate3d",[0,0,1],45)])
ground = nmesh.box( [-1,-1,-0.3],[1,1,1] )
bbox = [[-2,-2,-0.3],[2,2,4]]
mesh = nmesh.mesh(objects=[ground,box1],bounding_box=bbox,a0=0.5)
mesh.save("rotate3d.nmesh")
# visualise in MayaVi
vis =nmesh.visual.show_bodies_mayavi(mesh)
nmesh.visual.export_visualisation(vis,"rotate3d.eps")
import nmesh P2 = [0,4] #center of 'circle' 2 R2 = 3 #radius of 'circle' 2 P1 = [0,0] #center of 'circle' 1 R1 = 5 #radius of 'circle' 1 frustum = nmesh.conic( P1, R1, P2, R2 ) bbox = [[-5,0],[5,4]] mesh = nmesh.mesh(objects=[frustum], bounding_box=bbox) nmesh.visual.plot2d_ps( mesh, "frustum.ps")
# (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)
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)
import nmesh
# rotation of the object is performed
# around the [0,0,1] axis (z-axis).
box = nmesh.box( [0,0,0],[2,1,1], transform=[("rotate",[0,1],0)])
bbox = [[-1,-1,-1],[3,3,3]]
mesh = nmesh.mesh(objects=[box],bounding_box=bbox,mesh_bounding_box=False,a0=0.5)
mesh.save('rotate.nmesh')
#create 3d-plot of surfaces and export eps
vis=nmesh.visual.show_bodies_mayavi(mesh)
nmesh.visual.export_visualisation(vis,"rotate.eps")
## pylab.title('Mesh quality: 2*inradius/circumradius')
## pylab.xlabel('Quality')
## pylab.ylabel('Number of occurrences')
## pylab.ioff()
# increment the call counter
#globals()['call_counter'] = globals()['call_counter'] + 1
# to run unattended, comment out the following 2 lines
#pylab.draw()
#raw_input('Hit enter to continue...')
# create the mesh and visualise it every n steps
N = 10
mesh = nmesh.mesh(objects=[box, cone],
a0=rod,
bounding_box=bbox,
callback=(my_function, N))
# show the finished mesh
mesh_info = mesh.tolists()
# to visualise without writing to disk, uncomment this section
vtkData, points, simplices, simplexIndicies, icradii, ccradii = nmesh.visual.mesh2vtk(
mesh_info, VTKonly=False)
in2circ = nmesh.visual.findRatios(icradii, ccradii, factor=2) #2D mesh
vtkData = nmesh.visual.append2vtk(vtkData, in2circ, "2*inradius/circumradius")
globals()['v'].close_all()
globals()['v'] = nmesh.visual.mesh2mayavi(vtkData,
myv=globals()['v'],
lut_range=(0, 1))
m2 = v.load_module('SurfaceMap', 0)
import nmesh
cigar = nmesh.ellipsoid([4, 2])
bbox = [[-5, -5], [5, 5]]
mesh = nmesh.mesh(objects=[cigar], bounding_box=bbox, mesh_bounding_box=True)
mesh.save("tutorial2.nmesh")
nmesh.visual.plot2d_ps(mesh, "tutorial2.ps")
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")
import nmesh P2 = [0, 4] #center of 'circle' 2 R2 = 3 #radius of 'circle' 2 P1 = [0, 0] #center of 'circle' 1 R1 = 5 #radius of 'circle' 1 frustum = nmesh.conic(P1, R1, P2, R2) bbox = [[-5, 0], [5, 4]] mesh = nmesh.mesh(objects=[frustum], bounding_box=bbox) nmesh.visual.plot2d_ps(mesh, "frustum.ps")
