def mesh_it(self, rod_length = 0.5 , driver = [],mesher = [], bbox = [], density = "", visual = False, angles = False, save = []):
"""mesh_it(rod_length:float, driver, mesher, \
bbox:[float list,float list]), density, visual:bool,
save:string list).
Function to mesh the present object(s). The rod_length
is the desired length of the connections between the mesh nodes,
a value which is weighted with the C function density. The bbox
defines the outer boundary box of the mesh. The flag visual
consents to visualise the mesh during its relaxation process,
and it can be saved specifying the file (with format) in the save
list.
Possible formats are postscript file(s) ("ps" extension) (2D only),
vtk file(s) ("vtk" extension) (included the ones created at every
visualization step) and "pyfem" format ("dat" extension).
The function returns the mesh data in a python list of lists
(the content is clear once they are inspected).
"""
self.rod = rod_length
self.density = density
if mesher == []:
self.mesher = ocaml.mesher_defaults
else:
self.mesher = mesher.my_mesher
self.__file_vtk = ""
self.__file_ps = ""
self.__file_dat = ""
self.__file_png = ""
globals()['fig_number']=0
globals()['angles_time']=[]
globals()['default_iterations'] = 200
def check_save():
"""Function to check if the mesh has to be saved
in any format.
"""
# print "check_save"
if len(save)>0:
for filename in save:
if filename[-3:]=="dat":
self.__file_dat = filename
elif filename[-3:]=="vtk":
self.__file_vtk = filename
elif filename[-3:]==".ps":
self.__file_ps = filename
elif filename[-3:]=="png":
self.__file_png = filename
else:
ValueError ("wrong extension in save file name")
# print self.__file_vtk, self.__file_ps, self.__file_dat, self.__file_png
if visual: # Initialisation of mayavi if argument visual = True
# print "load mayavi"
import mayavi, pylab # Tk error without pylab
self.myv = mayavi.mayavi()
def check_vtk(nr_piece,n,mesh):
# print "check_vtk -- 0"
if visual or self.__file_vtk!="":
# print "mesh_info"
mesh_info = ocaml.mesh_plotinfo(mesh)
# print "check_vtk -- 1"
v = self._mesh2vtk(mesh_info,self.__file_vtk,"-"+str(nr_piece),"-"+str(n))
# print "check_vtk -- 2"
if visual:
# print "visual"
# Function executed for argument visual = True
self.myv.close_all()
vd = self.myv.open_vtk_data(v)
dvm = self.myv.get_current_dvm()
mm = dvm.get_current_module_mgr()
md = self.myv.load_module('SurfaceMap',0)
# reverse LUT
luthandler = mm.get_scalar_lut_handler()
luthandler.set_lut_red_blue()
# display legend, vertically with shadow effect
luthandler.sc_bar.SetVisibility(1)
luthandler.sc_bar.GetTitleTextProperty().SetShadow(1)
luthandler.sc_bar.GetLabelTextProperty().SetShadow(1)
luthandler.sc_bar.GetPositionCoordinate().SetValue(0.01,0.15)
luthandler.sc_bar.SetOrientationToVertical()
luthandler.sc_bar.SetWidth(0.14)
luthandler.sc_bar.SetHeight(0.85)
# luthandler.sc_bar.SetTitle('in2circ')
self.myv.renwin.z_plus_view()
vd2 = self.myv.open_vtk_data(v)
dvm = self.myv.get_current_dvm()
mm = dvm.get_current_module_mgr()
md2 = self.myv.load_module('SurfaceMap',0)
md2.mapper.ScalarVisibilityOff()
md2.actor.GetProperty().SetRepresentationToWireframe()
self.myv.renwin.z_plus_view()
self.myv.Render()
# if angles analysis has been requested plot histogram in pylab now
if angles:
angles_data = self._findAngles(mesh_info)
n, bins, patches = pylab.hist(angles_data, range(0,180,5))
pylab.xlabel('Internal angle in degrees')
pylab.ylabel('Number of occurrences')
pylab.title('Histogram of internal angles of %d triangles' % (len(mesh_info[2][2])))
pylab.axvline(x=60, color='r')
pylab.savefig(self.__file_png[:-4]+str(globals()['fig_number'])+'.png')
globals()['fig_number'] = globals()['fig_number'] + 1
pylab.show() #(screws with Tk events)
pylab.clf()
# attempt to save time series of angles data for quality vs. time plot
# this temporary hack saves the median angle for the highest count bin
highest = 0
modal = 0
for i in range(len(n)):
if n[i] > highest:
highest = n[i]
modal = i
median = (bins[modal] + bins[modal-1])/2.
globals()['angles_time'].append(median)
raw_input('Hit Any Key to Continue')
def no_driver(nr_piece,n,mesh):
"""Function executed for argument visual = False
"""
# print "no_driver"
check_vtk(nr_piece,n,mesh)
pass
def fun_from_driver(nr_piece,n,mesh):
"""Function that glues together the user-defined
function and the (possible) visualisation of the
mesh during relaxation process.
"""
check_vtk(nr_piece,n,mesh)
# print "*********************fun_from_driver"
driver.driver_do(nr_piece,n,mesh) #user-defined function
check_save() # check if the mesh has to be saved
if driver == []: # no driver is given: use the default one
self.driver = ocaml.make_mg_gendriver(globals()['default_iterations'], no_driver)
else:
# print self.__file_vtk
self.driver = ocaml.make_mg_gendriver(driver.every_nr_steps,fun_from_driver)
if bbox != []: # overwrite bbox defined at object initialisation
self.bbox = bbox
# print self.bbox
# print self.obj
obj_length = len(self.obj) # number of objects to mesh
raw_mesh = ocaml.mesh_bodies_raw(self.driver,self.mesher,\
self.bbox[0],self.bbox[1],obj_length,\
self.obj,rod_length,self.density)
if self.__file_ps != "":
ocaml.mesh2d_ps(raw_mesh,self.__file_ps,[50.0,50.0,300.0,300.0])
if self.__file_dat != "":
ocaml.mesh_writefile(self.__file_dat,raw_mesh)
# to display final results in visual mode
if visual:
mesh_info = ocaml.mesh_plotinfo(raw_mesh)
v = self._mesh2vtk(mesh_info,self.__file_vtk)
self.myv.close_all()
vd = self.myv.open_vtk_data(v)
dvm = self.myv.get_current_dvm()
mm = dvm.get_current_module_mgr()
md = self.myv.load_module('SurfaceMap',0)
# reverse LUT
luthandler = mm.get_scalar_lut_handler()
luthandler.set_lut_red_blue()
# display legend, vertically with shadow effect
luthandler.sc_bar.SetVisibility(1)
luthandler.sc_bar.GetTitleTextProperty().SetShadow(1)
luthandler.sc_bar.GetLabelTextProperty().SetShadow(1)
luthandler.sc_bar.GetPositionCoordinate().SetValue(0.01,0.15)
luthandler.sc_bar.SetOrientationToVertical()
luthandler.sc_bar.SetWidth(0.14)
luthandler.sc_bar.SetHeight(0.85)
# luthandler.sc_bar.SetTitle('in2circ')
self.myv.renwin.z_plus_view()
vd2 = self.myv.open_vtk_data(v)
dvm = self.myv.get_current_dvm()
mm = dvm.get_current_module_mgr()
md2 = self.myv.load_module('SurfaceMap',0)
md2.mapper.ScalarVisibilityOff()
md2.actor.GetProperty().SetRepresentationToWireframe()
self.myv.renwin.z_plus_view()
self.myv.Render()
if self.__file_png:
# if angles analysis has been requested plot histogram in pylab now
if angles:
angles_data = self._findAngles(mesh_info)
n, bins, patches = pylab.hist(angles_data, range(0,180,5))
pylab.clf()
pylab.xlabel('Internal angle in degrees')
pylab.ylabel('Number of occurrences')
pylab.title('Histogram of internal angles of mesh triangles')
pylab.axvline(x=60, color='r')
pylab.savefig(self.__file_png[:-4]+str(globals()['fig_number'])+'.png')
globals()['fig_number'] = globals()['fig_number'] + 1
pylab.show() #(screws with Tk events)
# also save time plot of angles
pylab.clf()
total_iterations = globals()['default_iterations']*len(globals()['angles_time'])
xvalues = range(0,total_iterations,globals()['default_iterations'])
pylab.plot(xvalues,globals()['angles_time'],'k+')
pylab.hold(True)
pylab.plot(xvalues,globals()['angles_time'])
pylab.xlabel('Number of iterations')
pylab.ylabel('Modal internal angle (2D) in degrees')
pylab.title('Plot of mesh quality against time')
pylab.savefig(self.__file_png[:-4]+'_time.png')
raw_input('Hit Any Key to Exit.')
else:
mesh_info = ocaml.mesh_plotinfo(raw_mesh)
raw_input('Hit Any Key to Exit.')
def __init__(self, objects = [], rod_length = 0.5, bbox = [[],[]],
density="", periodic = False, visual = False, fixed_points = [],
fun=[], fun_call_interval = 1000):
""" Class to define the parameters for the meshing algorithm.
mesh(
objects:obj list - objects to be meshed
rod_length:float - desired length of connection between nodes
bbox:[float list,float list] - outer bounding box
density:string - density function of nodes ditribution
periodic:bool - periodic boundary conditions in the outer box
visual:bool - use of the visualisation package
fixed_points: float list list - set of fixed points to be used in the mesh
fun - function to be called every interval steps
fun_call_interval:int - interval of the function calling
).
The rod_length is the desired length of the connections between
the mesh nodes, a value which is weighted with the density function
(given in C code). The bbox defines the outer boundary box of the mesh.
The function fun is executed every fun_call_interval steps and its
arguments are
nr_piece = index of the meshing object
iteration_nr = number of iteration in the relaxation process
mesh = mesh as a python list of lists (value returned by mesh_it())
The visual flag and the periodic flag are used to visualise and impose
periodic boundary conditions on the outer box, respectively.
If periodic boundary conditions are used, the density function
must respect the related contraints.
"""
self.obj = []
if type(objects) == types.ListType :
for obj in objects:
self.obj.append(obj.obj)
else:
raise ValueError("Error: wrong list of objects to mesh.")
self.rod = rod_length
self.bbox = bbox
self.density = density
if periodic:
self.periodic = 1
else:
self.periodic = 0
if visual:
#import m.visual
pass
if fun == []:
self.fun_driver = self._default_fun
else:
self.fun_driver = fun
self.fun_call_interval = fun_call_interval
self.fixed_points = fixed_points
# add fixed points coming from objects
for obj in objects:
for pt in obj.fxd_pts:
self.fixed += pt
self.mesher = 0 # flag for default/copied mesher
self.my_mesher = ocaml.mesher_defaults # default mesher
self.driver = ocaml.make_mg_gendriver(self.fun_call_interval, self.extended_fun_driver)
self.raw_mesh = []
