Re: [Yade-users] [Question #341304]: Landing of a satellite
Question #341304 on Yade changed: https://answers.launchpad.net/yade/+question/341304 Status: Answered => Solved Jonathan Pergoli confirmed that the question is solved: Thanks Jan Stránský, that solved my question. -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #341304]: Landing of a satellite
Question #341304 on Yade changed:
https://answers.launchpad.net/yade/+question/341304
Status: Open => Answered
Jan Stránský proposed the following answer:
Hi Jonathan,
not studied your script very much in detail, but you may try:
- decrease number of cores (contrary to what one expects :-). Sometimes
using more cores actually make the simulation take longer time, see [1],
page 470.
- not using polyhedrons, as from its nature it takes much longer time to
evaluate them than spheres
- increase time step (instead of 0.5 use higher factor)
- increase particle size (increasing time step)
- decrease number of particle number (using some tricks with boundary
conditions etc.)
- decrease stiffness or increase mass to increase time step (but this
changes also the physics), perhaps increase mass of just a few smallest
particles if you use some PSD (cannot be determined from your script)
- use timing stats to check if some of PyRunner functions does not use too
much time (not likely since you call them not very often)
Anyway, none of the options I gave decrease the simulation time
drastically..
cheers
Jan
2016-08-12 18:17 GMT+02:00 Jonathan Pergoli <
question341...@answers.launchpad.net>:
> New question #341304 on Yade:
> https://answers.launchpad.net/yade/+question/341304
>
> Hi guys,
>
> I am performing simulation in which a satellite lands on the soil. The
> simulation deal with more than 70.000 particles and take a week to make 10
> seconds of simulations using 10 cores. I'd like to know if it is possible
> to speed it up.
> This is the code:
>
> from yade import utils,ymport,export,plot
> import math as m
>
>
> # Material
> E1=1e+8
> E2=5e+7
> mli=FrictMat(density=643,frictionAngle=0.1489,label="MLI",young=E2)
> MLI=O.materials.append(mli)
> gravel=FrictMat(density=1700,frictionAngle=0.7853,label="gravel",young=E1)
> GRAVEL=O.materials.append(gravel)
>
> # Ground
> s=ymport.textExt('1cm_0g2.txt',format='x_y_z_r')
> sphere=O.bodies.append(s)
>
>
> # Create a vector o spheres to eliminate those that have COG above the
> container
> for i in O.bodies:
> if isinstance(i.shape,Sphere):
> if i.state.pos[2]>.30:
> O.bodies.erase(i.id)
> print i.state.mass
> for i in O.bodies:
> if isinstance(i.shape,Sphere):
> if i.state.pos[2]<0:
> O.bodies.erase(i.id)
> for i in O.bodies:
> if isinstance(i.shape,Sphere):
> x=i.state.pos[0]
> y=i.state.pos[1]
> r=m.sqrt(x**2+y**2)
> if r>.75:
> O.bodies.erase(i.id)
>
> aa=[]
> for i in O.bodies:
> if isinstance(i.shape,Sphere):
> aa.append(i.id)
>
> print len(aa)
>
> # Cylinder
> hc=.30
> c=geom.facetCylinder((0,0,.15),radius=.75,height=hc,
> segmentsNumber=100,wallMask=6,material="gravel")
> O.bodies.append(c)
>
> # SAT
> a=.2774
> b=.2922
> c=.1973
> aa=a/2
> bb=b/2
> cc=c/2
> h=.65
> dist=0
> theta=0
> thetav=0
> v1=(aa,bb,c)
> v2=(aa,-bb,c)
> v3=(-aa,-bb,c)
> v4=(-aa,bb,c)
> v5=(aa,bb,0)
> v6=(aa,-bb,0)
> v7=(-aa,-bb,0)
> v8=(-aa,bb,0)
> V=[v1,v2,v3,v4,v5,v6,v7,v8]
> vz=.19
> R=[[m.cos(theta),0,m.sin(theta)],[0,1,0],[-m.sin(theta),0,m.cos(theta)]]
> v1=(R[0][0]*V[0][0]+R[0][1]*V[0][1]+R[0][2]*V[0][2],R[1][0]*
> V[0][0]+R[1][1]*V[0][1]+R[1][2]*V[0][2],R[2][0]*V[0][0]+R[
> 2][1]*V[0][1]+R[2][2]*V[0][2])
> v2=(R[0][0]*V[1][0]+R[0][1]*V[1][1]+R[0][2]*V[1][2],R[1][0]*
> V[1][0]+R[1][1]*V[1][1]+R[1][2]*V[1][2],R[2][0]*V[1][0]+R[
> 2][1]*V[1][1]+R[2][2]*V[1][2])
> v3=(R[0][0]*V[2][0]+R[0][1]*V[2][1]+R[0][2]*V[2][2],R[1][0]*
> V[2][0]+R[1][1]*V[2][1]+R[1][2]*V[2][2],R[2][0]*V[2][0]+R[
> 2][1]*V[2][1]+R[2][2]*V[2][2])
> v4=(R[0][0]*V[3][0]+R[0][1]*V[3][1]+R[0][2]*V[3][2],R[1][0]*
> V[3][0]+R[1][1]*V[3][1]+R[1][2]*V[3][2],R[2][0]*V[3][0]+R[
> 2][1]*V[3][1]+R[2][2]*V[3][2])
> v5=(R[0][0]*V[4][0]+R[0][1]*V[4][1]+R[0][2]*V[4][2],R[1][0]*
> V[4][0]+R[1][1]*V[4][1]+R[1][2]*V[4][2],R[2][0]*V[4][0]+R[
> 2][1]*V[4][1]+R[2][2]*V[4][2])
> v6=(R[0][0]*V[5][0]+R[0][1]*V[5][1]+R[0][2]*V[5][2],R[1][0]*
> V[5][0]+R[1][1]*V[5][1]+R[1][2]*V[5][2],R[2][0]*V[5][0]+R[
> 2][1]*V[5][1]+R[2][2]*V[5][2])
> v7=(R[0][0]*V[6][0]+R[0][1]*V[6][1]+R[0][2]*V[6][2],R[1][0]*
> V[6][0]+R[1][1]*V[6][1]+R[1][2]*V[6][2],R[2][0]*V[6][0]+R[
> 2][1]*V[6][1]+R[2][2]*V[6][2])
> v8=(R[0][0]*V[7][0]+R[0][1]*V[7][1]+R[0][2]*V[7][2],R[1][0]*
> V[7][0]+R[1][1]*V[7][1]+R[1][2]*V[7][2],R[2][0]*V[7][0]+R[
> 2][1]*V[7][1]+R[2][2]*V[7][2])
> p=utils.polyhedron((v1,v2,v3,v4,v5,v6,v7,v8),fixed=False,
> color=(.6,.45,0),material="MLI",wire=False)
> SAT=O.bodies.append(p)
> p.state.vel=(vz*m.sin(thetav),0,-vz*m.cos(thetav))
> p.state.ori=((0,-1,0),theta)
> p.state.pos=(-dist,0,h)
> Ixx=0.081026
> Iyy=0.10031
> Izz=0.12116
> p.state.inertia=(Ixx,Iyy,Izz)
> M=p.id
> r=m.sqrt(aa**2+bb**2)
> Rj=m.sqrt(r**2+cc**2)
> Ri=0.05
> Rr=Rj*Ri/(Rj+Ri)
> mu_rM=0.016
> mu_rG=2.05
>
[Yade-users] [Question #341304]: Landing of a satellite
New question #341304 on Yade:
https://answers.launchpad.net/yade/+question/341304
Hi guys,
I am performing simulation in which a satellite lands on the soil. The
simulation deal with more than 70.000 particles and take a week to make 10
seconds of simulations using 10 cores. I'd like to know if it is possible to
speed it up.
This is the code:
from yade import utils,ymport,export,plot
import math as m
# Material
E1=1e+8
E2=5e+7
mli=FrictMat(density=643,frictionAngle=0.1489,label="MLI",young=E2)
MLI=O.materials.append(mli)
gravel=FrictMat(density=1700,frictionAngle=0.7853,label="gravel",young=E1)
GRAVEL=O.materials.append(gravel)
# Ground
s=ymport.textExt('1cm_0g2.txt',format='x_y_z_r')
sphere=O.bodies.append(s)
# Create a vector o spheres to eliminate those that have COG above the container
for i in O.bodies:
if isinstance(i.shape,Sphere):
if i.state.pos[2]>.30:
O.bodies.erase(i.id)
print i.state.mass
for i in O.bodies:
if isinstance(i.shape,Sphere):
if i.state.pos[2]<0:
O.bodies.erase(i.id)
for i in O.bodies:
if isinstance(i.shape,Sphere):
x=i.state.pos[0]
y=i.state.pos[1]
r=m.sqrt(x**2+y**2)
if r>.75:
O.bodies.erase(i.id)
aa=[]
for i in O.bodies:
if isinstance(i.shape,Sphere):
aa.append(i.id)
print len(aa)
# Cylinder
hc=.30
c=geom.facetCylinder((0,0,.15),radius=.75,height=hc,segmentsNumber=100,wallMask=6,material="gravel")
O.bodies.append(c)
# SAT
a=.2774
b=.2922
c=.1973
aa=a/2
bb=b/2
cc=c/2
h=.65
dist=0
theta=0
thetav=0
v1=(aa,bb,c)
v2=(aa,-bb,c)
v3=(-aa,-bb,c)
v4=(-aa,bb,c)
v5=(aa,bb,0)
v6=(aa,-bb,0)
v7=(-aa,-bb,0)
v8=(-aa,bb,0)
V=[v1,v2,v3,v4,v5,v6,v7,v8]
vz=.19
R=[[m.cos(theta),0,m.sin(theta)],[0,1,0],[-m.sin(theta),0,m.cos(theta)]]
v1=(R[0][0]*V[0][0]+R[0][1]*V[0][1]+R[0][2]*V[0][2],R[1][0]*V[0][0]+R[1][1]*V[0][1]+R[1][2]*V[0][2],R[2][0]*V[0][0]+R[2][1]*V[0][1]+R[2][2]*V[0][2])
v2=(R[0][0]*V[1][0]+R[0][1]*V[1][1]+R[0][2]*V[1][2],R[1][0]*V[1][0]+R[1][1]*V[1][1]+R[1][2]*V[1][2],R[2][0]*V[1][0]+R[2][1]*V[1][1]+R[2][2]*V[1][2])
v3=(R[0][0]*V[2][0]+R[0][1]*V[2][1]+R[0][2]*V[2][2],R[1][0]*V[2][0]+R[1][1]*V[2][1]+R[1][2]*V[2][2],R[2][0]*V[2][0]+R[2][1]*V[2][1]+R[2][2]*V[2][2])
v4=(R[0][0]*V[3][0]+R[0][1]*V[3][1]+R[0][2]*V[3][2],R[1][0]*V[3][0]+R[1][1]*V[3][1]+R[1][2]*V[3][2],R[2][0]*V[3][0]+R[2][1]*V[3][1]+R[2][2]*V[3][2])
v5=(R[0][0]*V[4][0]+R[0][1]*V[4][1]+R[0][2]*V[4][2],R[1][0]*V[4][0]+R[1][1]*V[4][1]+R[1][2]*V[4][2],R[2][0]*V[4][0]+R[2][1]*V[4][1]+R[2][2]*V[4][2])
v6=(R[0][0]*V[5][0]+R[0][1]*V[5][1]+R[0][2]*V[5][2],R[1][0]*V[5][0]+R[1][1]*V[5][1]+R[1][2]*V[5][2],R[2][0]*V[5][0]+R[2][1]*V[5][1]+R[2][2]*V[5][2])
v7=(R[0][0]*V[6][0]+R[0][1]*V[6][1]+R[0][2]*V[6][2],R[1][0]*V[6][0]+R[1][1]*V[6][1]+R[1][2]*V[6][2],R[2][0]*V[6][0]+R[2][1]*V[6][1]+R[2][2]*V[6][2])
v8=(R[0][0]*V[7][0]+R[0][1]*V[7][1]+R[0][2]*V[7][2],R[1][0]*V[7][0]+R[1][1]*V[7][1]+R[1][2]*V[7][2],R[2][0]*V[7][0]+R[2][1]*V[7][1]+R[2][2]*V[7][2])
p=utils.polyhedron((v1,v2,v3,v4,v5,v6,v7,v8),fixed=False,color=(.6,.45,0),material="MLI",wire=False)
SAT=O.bodies.append(p)
p.state.vel=(vz*m.sin(thetav),0,-vz*m.cos(thetav))
p.state.ori=((0,-1,0),theta)
p.state.pos=(-dist,0,h)
Ixx=0.081026
Iyy=0.10031
Izz=0.12116
p.state.inertia=(Ixx,Iyy,Izz)
M=p.id
r=m.sqrt(aa**2+bb**2)
Rj=m.sqrt(r**2+cc**2)
Ri=0.05
Rr=Rj*Ri/(Rj+Ri)
mu_rM=0.016
mu_rG=2.05
KN=E1*2*Ri*E1*2*Ri/(E1*2*Ri+E1*2*Ri)#6.5e+4
KR=3*Ri**2*mu_rG**2*KN/4
print "SAT's mass = ",p.state.mass
print "SAT's position = ",p.state.pos
print "SAT's orientation = ",p.state.ori
print "SAT's inertia = ",p.state.inertia
print "Timestep = ",O.dt
# Functions
def forces():
# rotation of axis
q1=p.state.ori[0]
q2=p.state.ori[1]
q3=p.state.ori[2]
q4=p.state.ori[3]
RR=[[q1**2-q2**2-q3**2+q4**2,2*(q1*q2+q3*q4),2*(q1*q3-q2*q4)],[2*(q1*q2-q3*q4),-q1**2+q2**2-q3**2+q4**2,2*(q2*q3+q1*q4)],[2*(q1*q3+q2*q4),2*(q2*q3-q1*q4),-q1**2-q2**2+q3**2+q4**2]]
e1=(RR[0][0],RR[0][1],RR[0][2])
e2=(RR[1][0],RR[1][1],RR[1][2])
e3=(RR[2][0],RR[2][1],RR[2][2])
massa1=0
massa2=0
massa3=0
for i in O.bodies:
if isinstance(i.shape,Sphere):
if i.state.vel[2]>.001:
massa1+=i.state.mass
if i.state.pos[2]>.4:
massa2+=i.state.mass
if i.state.vel[2]>.01:
massa3+=i.state.mass
# forces
#Fx=utils.sumForces([MASCOT],e1)
#Fy=utils.sumForces([MASCOT],e2)
#Fz=utils.sumForces([MASCOT],e3)
#Tx=utils.sumTorques([MASCOT],axis=e1,axisPt=(p.state.pos[0]-aa,p.state.pos[1],p.state.pos[2]))
