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Re: [Question #247061]: Slow start-up time for small particles

 

Question #247061 on Yade changed:
https://answers.launchpad.net/yade/+question/247061

    Status: Answered => Open

Emon Mitra is still having a problem:
Sorry for the late reply, I think you're right about the number of
particles. I've attached the code below, is there any way to speed it up
while maintaining the number of particles?

# gravity deposition, continuing with oedometric test after stabilization
# shows also how to run parametric studies with yade-batch

# The components of the batch are:
# 1. table with parameters, one set of parameters per line (ccc.table)
# 2. utils.readParamsFromTable which reads respective line from the parameter file
# 3. the simulation muse be run using yade-batch, not yade
#
# $ yade-batch --job-threads=1 03-oedometric-test.table 03-oedometric-test.py
#

# load parameters from file if run in batch
# default values are used if not run from batch
utils.readParamsFromTable(rMean=.002,rRelFuzz=.3,maxLoad=1e7,minLoad=1e4)
# make rMean, rRelFuzz, maxLoad accessible directly as variables later
from yade.params.table import *

# create box with free top, and ceate loose packing inside the box
from yade import pack, plot, qt
O.bodies.append(utils.geom.facetBox((.5,.5,.5),(.5,.5,.5),wallMask=31))
sp=pack.SpherePack()
sp.makeCloud((0,0,0),(1,1,1),rMean=rMean,rRelFuzz=rRelFuzz)
sp.toSimulation()

O.engines=[
   ForceResetter(),
   # sphere, facet, wall
   InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb(),Bo1_Wall_Aabb()]),
   InteractionLoop(
      # the loading plate is a wall, we need to handle sphere+sphere, sphere+facet, sphere+wall
      [Ig2_Sphere_Sphere_L3Geom(),Ig2_Facet_Sphere_L3Geom(),Ig2_Wall_Sphere_L3Geom()],
      [Ip2_FrictMat_FrictMat_FrictPhys()],
      [Law2_L3Geom_FrictPhys_ElPerfPl()]
   ),
   GravityEngine(gravity=(0,0,-9.81)),
   NewtonIntegrator(damping=0.5),
   # save data for Paraview
   VTKRecorder(fileName='3d-vtk-',recorders=['all'],iterPeriod=1000),
   # save data from Yade's own 3d view
   qt.SnapshotEngine(fileBase='3d-',iterPeriod=200,label='snapshot'),

   # the label creates an automatic variable referring to this engine
   # we use it below to change its attributes from the functions called
   PyRunner(command='checkUnbalanced()',realPeriod=2,label='checker'),
]
O.dt=.5*utils.PWaveTimeStep()

# the following checkUnbalanced, unloadPlate and stopUnloading functions are all called by the 'checker'
# (the last engine) one after another; this sequence defines progression of different stages of the
# simulation, as each of the functions, when the condition is satisfied, updates 'checker' to call
# the next function when it is run from within the simulation next time

# we must open the view explicitly (limitation of the qt.SnapshotEngine)
qt.View()

# check whether the gravity deposition has already finished
# if so, add wall on the top of the packing and start the oedometric test
def checkUnbalanced():
   # at the very start, unbalanced force can be low as there is only few contacts, but it does not mean the packing is stable
   if O.iter<5000: return 
   # the rest will be run only if unbalanced is < .1 (stabilized packing)
   if utils.unbalancedForce()>.1: return 
   # add plate at the position on the top of the packing
   # the maximum finds the z-coordinate of the top of the topmost particle
   O.bodies.append(utils.wall(max([b.state.pos[2]+b.shape.radius for b in O.bodies if isinstance(b.shape,Sphere)]),axis=2,sense=-1))
   global plate        # without this line, the plate variable would only exist inside this function
   plate=O.bodies[-1]  # the last particles is the plate
   # Wall objects are "fixed" by default, i.e. not subject to forces
   # prescribing a velocity will therefore make it move at constant velocity (downwards)
   plate.state.vel=(0,0,-.1)
   # start plotting the data now, it was not interesting before
   O.engines=O.engines+[PyRunner(command='addPlotData()',iterPeriod=200)]
   # next time, do not call this function anymore, but the next one (unloadPlate) instead
   checker.command='unloadPlate()'
   utils.makeVideo(snapshot.snapshots,'3d.mpeg',fps=10,bps=10000)

def unloadPlate():
   # if the force on plate exceeds maximum load, start unloading
   if abs(O.forces.f(plate.id)[2])>maxLoad:
      plate.state.vel*=-1
      # next time, do not call this function anymore, but the next one (stopUnloading) instead
      checker.command='stopUnloading()'

def stopUnloading():
   if abs(O.forces.f(plate.id)[2])<minLoad:
      # O.tags can be used to retrieve unique identifiers of the simulation
      # if running in batch, subsequent simulation would overwrite each other's output files otherwise
      # d (or description) is simulation description (composed of parameter values)
      # while the id is composed of time and process number
      plot.saveDataTxt(O.tags['d.id']+'.txt')
      O.pause()
   
def addPlotData():
   if not isinstance(O.bodies[-1].shape,Wall):
      plot.addData(); return
   Fz=O.forces.f(plate.id)[2]
   plot.addData(Fz=Fz,w=plate.state.pos[2]-plate.state.refPos[2],unbalanced=utils.unbalancedForce(),i=O.iter)

# besides unbalanced force evolution, also plot the displacement-force diagram
plot.plots={'i':('unbalanced',),'w':('Fz',)}
plot.plot()
  

O.run()
# when running with yade-batch, the script must not finish until the simulation is done fully
# this command will wait for that (has no influence in the non-batch mode)
utils.waitIfBatch()

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