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[rayolau <question268691@xxxxxxxxxxxxxxxxxxxxx>]

New question #268691 on Yade:
https://answers.launchpad.net/yade/+question/268691

Hi guys!

I try to study the displacement of various spheres ( with different weight ) when on they apply the same force, on a surface which previously has been created and is composed of other spheres.

My problem is the IterPeriod of the PyRunner function that I create for apply the force on the sphere that I want, in this case, green spheres.

If I put the period = 1 , the force is constantly applied .How I can apply the force one once time only? PyRunner(command='force()',
		¿?¿?¿?iterPeriod=¿?¿?¿,initRun=True,label='checker'),

My first choice was to put a high period (100000000 for example), but this way , the green sphere falls on the surface of spheres before the force is applied . What I need is to apply a force on green particle when it is "in the air " to describe a parabolic movement to fall on the surface and stop.

The second PyRunner is to store the position data ( x , y, z) and the green particle velocity .

Thanks in advance =)

the code:

O.load('/path/spheresurface.yade')

#/////////////////////////////////////////////////////
#////////////////// materials \\\\\\\\\\\\\\\\\\\\\\\
#/////////////////////////////////////////////////////

MatBal=O.materials.append(FrictMat(
	young=27e9,poisson=0.30,density=1000,
	frictionAngle=0.7,label='mat1'))

#/////////////////////////////////////////////////////
#////////////////// green sphere\\\\\\\\\\\\\\\\\\\\
#/////////////////////////////////////////////////////

### green sphere

O.bodies.append(utils.sphere((0.108,0.2289647116,0.7175),0.0199647116,color=(0,1,0),material='mat1'))


#/////////////////////////////////////////////////////
#//////////////// force on green sphere\\\\\\\\\\\\
#/////////////////////////////////////////////////////

def force():
	piedraensayo=[]
			
###force on green sphere
	for i in range(0,len(O.bodies)):
		b=O.bodies[i]
		if O.bodies[i].shape.color==(0,1,0):
			piedraensayo.append([i])			
			id_ball=i			
			fx=1
			fy=0
			fz=0
			O.forces.addF(id_ball, (fx, fy, fz))


#/////////////////////////////////////////////////////
#///////save position and velocity \\\\\\\\\\\\\\\\\
#/////////////////////////////////////////////////////
def guardar():
	if O.iter==0:
		global paso
		matriz1=[]
		for i in range(0,len(O.bodies)):
			b=O.bodies[i]
			if O.bodies[i].shape.color==(0,1,0):
				matriz1.append([i,b.state.pos[1],b.state.pos[1],b.state.pos[2],b.state.vel.norm()])
				np.savetxt('pruebaVERDE.out',matriz1,delimiter=',')
				
		paso=1

	if paso==1 and O.time>0.2:

		matriz2=[]
		for i in range(0,len(O.bodies)):
			b=O.bodies[i]
			if O.bodies[i].shape.color==(0,1,0):
				matriz2.append([i,b.state.pos[0],b.state.pos[1],b.state.pos[2],b.state.vel.norm()])
				np.savetxt('pruebaVERDE2.out',matriz2,delimiter=',')
				
		paso=paso+1

	if paso==2 and O.time>0.4:

		matriz3=[]
		for i in range(0,len(O.bodies)):
			b=O.bodies[i]
			if O.bodies[i].shape.color==(0,1,0):
				matriz3.append([i,b.state.pos[0],b.state.pos[1],b.state.pos[2],b.state.vel.norm()])
				np.savetxt('pruebaVERDE3.out',matriz3,delimiter=',')
				
		paso=paso+1

#/////////////////////////////////////////////////////
#///////////////////// engines \\\\\\\\\\\\\\\\\\\\\\\
#/////////////////////////////////////////////////////

O.engines=[	
	ForceResetter(),
	InsertionSortCollider(
		[Bo1_Sphere_Aabb(),
			Bo1_Facet_Aabb(),
			Bo1_Box_Aabb(),
			Bo1_Wall_Aabb()]),
	InteractionLoop(
		[Ig2_Sphere_Sphere_ScGeom(),
			Ig2_Facet_Sphere_ScGeom(),
			Ig2_Wall_Sphere_ScGeom(),
			Ig2_Box_Sphere_ScGeom()],
		[Ip2_FrictMat_FrictMat_FrictPhys()],
		[Law2_ScGeom_FrictPhys_CundallStrack()]
	),
	PyRunner(command='force()',
		iterPeriod=1,initRun=True,label='checker'),
	PyRunner(command='guardar()',
		iterPeriod=1,initRun=True,label='checker'),
	NewtonIntegrator(damping=0.5,gravity=(0,-9.81,0),label='newton'),
	yade.qt.SnapshotEngine(fileBase='3d-',iterPeriod=1000,label='snapshot')
]
O.dt=utils.PWaveTimeStep()


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