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[gaoxuesong <question688789@xxxxxxxxxxxxxxxxxxxxx>]

New question #688789 on Yade:
https://answers.launchpad.net/yade/+question/688789

Hi. I want to try some parameters that come into play at a late time point, like 1.0s. So i save the simulation at 0.9s and then restart it by O.load() method, followed by trying new parameters. 

I have a roller constructed by facets doing translation and rotation controlled by RotationEngine and TranslationEngine, respectively. The parameter of "ids" in those engines is used to bond the engine to the roller (facets).  

I use the pickle module to save the roller factets ids into a file during the first run and load these ids again in the restart run. So in the new run, the engines enable to find those roller facets to control. I have checked those ids of facets and they are right. 

The problem is that the roller can not rotate or translate in the restart run.  

My MWE is as the following, ( the scenario) 
https://drive.google.com/file/d/1kQN9ZHgJzktLZQ57nWBMbXDa2joxDzUz/view?usp=sharing )
the first run saves every 0.05s and the restart run loads data at time 0f 0.3s. Because the rotation is active till 0.4s, the roller in the restart run should rotate at the beginning. It's stationary yet. 

########## the first run  to save at a time point ######## ##

#!/usr/bin/python
#-*- coding: utf-8 -*-
from yade import pack,geom,utils  
import numpy as np
from yade import qt 

## material 
matSph = CohFrictMat(density=8e11, young=193e9, poisson=0.3)
Mat = O.materials.append(matSph)

## roller 
radiusSweeper = 0.3e-3 
lengthSweeper = 1.0e-3 
numSweeperParts = 20   
Sweeper=[]
for i in np.linspace(0, 2*pi, num=numSweeperParts, endpoint=True):
	Sweeper.append(Vector3(radiusSweeper*cos(-i), 0.0, radiusSweeper*sin(-i)+1.3e-3))
SweeperP=[Sweeper, [p+Vector3(0.0,lengthSweeper,0.0) for p in Sweeper]]
SweeperPoly = pack.sweptPolylines2gtsSurface(SweeperP, threshold=1e-7)
SweeperIDs = O.bodies.append(pack.gtsSurface2Facets(SweeperPoly, wire=False, material=Mat))
## save roller facets' id for restart ### 
import pickle 
fd = open('rollerids.txt', 'wb')
pickle.dump(SweeperIDs, fd)
fd.close() 

## platform 
O.bodies.append(geom.facetBox((2.0e-3,0.5e-3,0.8e-3),(2.0e-3,0.5e-3,0.2e-3), wallMask=63, wire=False, material=Mat))
 
### process parameters 
velsw = 2.5e-3 ## translation vel 
angvelsw = -50.0  ## rotation vel  
t1 = 0.4 ## 0~0.2s, rotation + translation 
t2 = 0.8 ## 0.2~0.4, translation   
def change_motion():
    if O.time < t1:
        rotaEngineSw.dead = False 
        transEngineSw.dead = False
        rotaEngineSw.zeroPoint = (O.time*velsw, 0, 1.30e-3)
    elif O.time < t2:
        rotaEngineSw.angularVelocity = 0.0   
        transEngineSw.velocity = velsw 
    else:
        transEngineSw.velocity = 0.0 
        
## save per 0.05s 
svdt = 0.05    
saveTime = 0 
def svfun():
    global svdt, saveTime  
    if O.time> saveTime:
        O.save('time-'+str(O.time)[:4])
        saveTime += svdt  
    if O.time>1.2:
        O.pause() 
        
O.engines=[
	ForceResetter(),
	InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]),
	InteractionLoop(
     	   [Ig2_Sphere_Sphere_ScGeom6D(),Ig2_Facet_Sphere_ScGeom6D()],
     	   [Ip2_CohFrictMat_CohFrictMat_CohFrictPhys()],
      	   [Law2_ScGeom6D_CohFrictPhys_CohesionMoment()]
   	),
    PyRunner(iterPeriod=100,command='change_motion()'),
    RotationEngine(dead=True, label='rotaEngineSw', rotateAroundZero=True, zeroPoint=(0,0,1.30e-3), angularVelocity=angvelsw, rotationAxis=[0,1,0], ids=SweeperIDs)+ \
    TranslationEngine(dead=True, label='transEngineSw', translationAxis=[1,0,0], velocity=velsw, ids=SweeperIDs),
    NewtonIntegrator(damping=0.75, exactAsphericalRot=True, gravity=(0,0,-9.81)),
    PyRunner(iterPeriod=100,command='svfun()'),
]

## particles 
sp=pack.SpherePack()
sp.makeCloud((0.5e-3,0,1.0e-3),(2.0e-3,1e-3,1.4e-3),rMean=40e-6,rRelFuzz=0.5)
sp.toSimulation(material=Mat)

O.dt = 0.85*utils.PWaveTimeStep()

#O.run()


######## the restart run ######## 
##########################

#!/usr/bin/python
#-*- coding: utf-8 -*-
from yade import pack,geom,utils  
import numpy as np
from yade import qt 

## load a saved data 
O.load('time-0.30')

import pickle 
fd = open('rollerids.txt', 'rb')
SweeperIDs = pickle.load(fd) 
fd.close()

### process parameters 
velsw = 2.5e-3 ## translation vel 
angvelsw = -50.0  ## rotation vel  
t1 = 0.4 ## 0~0.2s, rotation + translation 
t2 = 0.8 ## 0.2~0.4, translation   
def change_motion():
    if O.time < t1:
        rotaEngineSw.dead = False 
        transEngineSw.dead = False
        rotaEngineSw.zeroPoint = (O.time*velsw, 0, 1.30e-3)
    elif O.time < t2:
        rotaEngineSw.angularVelocity = 0.0   
        transEngineSw.velocity = velsw 
    else:
        transEngineSw.velocity = 0.0 
        
## save per 0.05s 
svdt = 0.05    
saveTime = 0 
def svfun():
    global svdt, saveTime  
    if O.time>saveTime:
        O.save('time-r-'+str(O.time)[:4])
        saveTime += svdt  
    if O.time>1.2:
        O.pause() 
O.engines=[
	ForceResetter(),
	InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]),
	InteractionLoop(
     	   [Ig2_Sphere_Sphere_ScGeom6D(),Ig2_Facet_Sphere_ScGeom6D()],
     	   [Ip2_CohFrictMat_CohFrictMat_CohFrictPhys()],
      	   [Law2_ScGeom6D_CohFrictPhys_CohesionMoment()]
   	),
    PyRunner(iterPeriod=100,command='change_motion()'),
    RotationEngine(dead=True, label='rotaEngineSw', rotateAroundZero=True, zeroPoint=(0,0,1.30e-3), angularVelocity=angvelsw, rotationAxis=[0,1,0], ids=SweeperIDs)+ \
    TranslationEngine(dead=True, label='transEngineSw', translationAxis=[1,0,0], velocity=velsw, ids=SweeperIDs),
    NewtonIntegrator(damping=0.75, exactAsphericalRot=True, gravity=(0,0,-9.81)),
    PyRunner(iterPeriod=100,command='svfun()'),
]

O.dt = 0.85*utils.PWaveTimeStep()

#O.run()


#### code finishing ### 

Thanks! 












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