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## [Question #697744]: Increase particle radiues

```New question #697744 on Yade:

Hi,

I am increasing my particle radius at each 100 iteration. But particle radius is not updating when using body.state.radius to update it.

Best,
Mithu

Here is my code:

#!/usr/bin/env python
#encoding: ascii

# Testing of the Deformation Enginge with Luding Contact Law
# Modified Oedometric Test
# The reference paper [Haustein2017]

from __future__ import print_function
from yade import utils, plot, timing
import pandas as pd
import numpy as np
from scipy.integrate import odeint

o = Omega()

# Physical parameters
fr = 0.54
rho = 1050
Diameter = 0.0012
D=Diameter
r1 = Diameter/2
#r2 = Diameter/2
k1 = 100000
kp = 12.0*k1
kc = k1 * 0.1
ks = k1 * 0.1
DeltaPMax = Diameter/3.0
Chi1 = 0.34

o.dt = 1.0e-7
particleMass = 4.0/3.0*math.pi*r1*r1*r1*rho

Vi1 = math.sqrt(k1/particleMass)*DeltaPMax*Chi1
PhiF1=0.999
#PhiF1 = DeltaPMax*(kp-k1)*(r1+r2)/(kp*2*r1*r2)

Cyl_height=0.045

Comp_press= 0.5e8
Comp_force=Comp_press*cross_area
i=0

# swelling_mode function
def model(r,t,Q_max,rho_t,rho_w,r_0,D):
Q=((rho_w*(r**3))/(rho_t*(r_0**3)))-(rho_w/rho_t)+1;
drdt =((D*rho_t)/(r*rho_w))*((Q_max-Q)/Q);
return drdt

P=[1.45,rho,1000,r1,396.36e-12]
time_save=[]
#*************************************

mat1 = O.materials.append(LudingMat(frictionAngle=fr, density=rho, k1=k1, kp=kp, ks=ks, kc=kc, PhiF=PhiF1, G0 = 0.0))

# Spheres for compression and walls
sp=pack.SpherePack()
sp.makeCloud((-3.0*Diameter,-3.0*Diameter,-18*Diameter),(3.0*Diameter,3.0*Diameter,18.0*Diameter), rMean=Diameter/2.0,rRelFuzz=0.18,num=527)
sp.toSimulation(material=mat1)

o.engines = [
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=1.05),
Bo1_Wall_Aabb(),
Bo1_Facet_Aabb()
]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=1.05),
Ig2_Facet_Sphere_ScGeom(),
Ig2_Wall_Sphere_ScGeom()],
[Ip2_LudingMat_LudingMat_LudingPhys()],
[Law2_ScGeom_LudingPhys_Basic()]
),
NewtonIntegrator(damping=0.1, gravity=[0, 0, 0]),
PyRunner(command='ParticleSwelling()', iterPeriod=100, label="fCheck"),
#DeformControl(label="DefControl")
]

def ParticleSwelling():
time_current=O.iter*o.dt
time_save.append(time_current)
for b in O.bodies:
if isinstance(b.shape, Sphere):
t=[0,time_current-time_save[0]]
r= odeint(model,P[3],t,args=(P[0],P[1],P[2],P[3],P[4],))