Re: [Yade-users] [Question #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Status: Answered => Solved yang yi confirmed that the question is solved: Bruno Chareyre (bruno-chareyre) Thank you very much. It is not a good news for me. OK. I will try. Thank youo -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Bruno Chareyre proposed the following answer: > the parallel programming, means there are 98 programming copies, and each copy for a cores. If my understanding right or not? More or less.[1] > If I increase the core, this kind of calculation can be improved? In general yes. > The next episode must based on the current training result. Then you will have to improve your program. It is AFAIK the only way to gain time, based on your description. Bruno [1] https://en.wikipedia.org/wiki/Parallel_programming_model#Shared_memory -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 yang yi posted a new comment: To Bruno Chareyre (bruno-chareyre): Thank you very much. I test -j1 and -j8 on my PC, yes. the speed is the same. And I test the command ~$ export OMP_NUM_THREADS=1 and the result is the same with you. I explain my understanding about your mean: the parallel programming, means there are 98 programming copies, and each copy for a cores. If my understanding right or not? If my understanding is right, I have the following question. I know that my programming cannot parallelly operated. I just want the calculation of particles in a programming is parallel, such as calculation the pressure between the particles. Because there are huge number of particles, so the calculation is huge. If I increase the core, this kind of calculation can be improved? Thank you for you second suggestion. Actually, the algorithm can not be trained parallelly. The aim of the training is to make the parameters to close the optimal value. The next episode must based on the current training result. Thank you very much. -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Bruno Chareyre proposed the following answer: > I understand you suggestion to get the optimal price of cores. But now for me, to get the fastest speed of the simulation is the aim. Yes. That's exactly my point. It could be that the fastest is -j1, or that it is just equal. Here is some bad news: if you write an ordinary python program and you assign more than one openMP thread to it, the change of execution time will be null. You can try on your server by running a minimal program, just try this in the command line: :~$ export OMP_NUM_THREADS=1 :~$ time python3 -c "for k in range(int(1e7)): a=k**0.124" real0m2.240s user0m2.190s sys 0m0.009s Then: :~$ export OMP_NUM_THREADS=96 :~$ time python3 -c "for k in range(int(1e7)): a=k**0.124" real0m2.190s user0m2.181s sys 0m0.008s That's how programming works in many cases. The variable OMP_NUM_THREADS is even not used when python runs. It is the same for your PyRunners. The fact that yade is parallel doesn't make *your* program parallel. Here is the good news: If you have to train your algorithm on many realizations then you can train 96 cases simultaneously (assuming RAM is enough). Which will be *much* faster. You can, either, hire colleagues to have more hands clicking the open/close for 96 planks (will need many keyboards/mices with long cables for social distancing), or (safer) do it with hard numbers as Jan suggested. If really you have no choice but running one single script at a time, then you need to re-think what your simulation script is doing - with a good idea of where/how time is spent. B. -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 yang yi posted a new comment: To Jan Stránský (honzik) and Bruno Chareyre (bruno-chareyre) : Thank you very much for you professional response. My the simulation process likes this: The two kinds of particles falling down and the plank will open or close according to the rate of one kind of particle. My job is to design the control algorithm of the plank. Because if the martial parameter of particles different, the falling speed of particles and action speed of plank is different. So I must to check if the two speeds are matching or not. And, because I just want to verify the control algorithm, so I hope the falling process could be as fast as possible since training the control algorithm needs a great number of episodes, maybe need two days or three days. So we buy the server. And the server is just for this simulation now. That is why I hope to use the maximum core of this server. I understand you suggestion to get the optimal price of cores. But now for me, to get the fastest speed of the simulation is the aim. I am the author of the posted script. Actually, I just know the running model of pytorch and just to call the neural network package, I do not deeply to learning what the script structure is the best for matching YADE.Bruno Chareyre is right, the pyrunner decide the runing speed. But my question is I use the same OS, the same script, and same configuration in both of PC and server, if I get 3D show, the speed in PC is faster than in the server. However, if I closed the 3D show, the calculation speed of server is faster than PC. Jan Stránský told me the simulation-world speed is the same regardless of the 3D show open or close and the simulation state definitely is not influenced by the 3D view. So it makes me very confusion. without 3D show the calculation speed of server is faster than PC, that mean the iteration number is more than PC. so the 3D view checks the locations roughly, we could find the falling speed is faster than PC. But actually, I find the speed in the server is slower than in PC. So, I will try like this way, to storage the location and check what will happen. Thank you very much -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Bruno Chareyre proposed the following answer: > Start the script by the 'start' button on the Controller(), without "3D" show [...] did 10 iteration test [...] Because I get the time by hand, so there is errors How do you get time "by hand" for 10 iterations after clicking "start"? You manage to click "stop" right in time? -j48 24.51s -j52 24.55s -j60 26.53s -j88 23.29s \ 23.12s -j90 23.27s \ 23.72s -j96 23.91s Mmmmh... sorry but, why do you refuse to measure -j1? Is it against some sort of religion? I have seen this "-jNmax must be better" approach before, with people doing it always - even at the price of slowing down their daily workstation. It is in fact a very bad practice. It could as well be slower! If you don't try you'll never know and you will waste 96 cores 24/24 for no good. It is obvious in your numbers than you gain *nothing* in this range of -j. We will not discuss 5%, especially considering time measurements by hand. If I may ask, are you the author of the script you posted? Because I think that's what needs inspection first. Is torch module parallel? Also there are many pyRunner's inside, even one with iterPeriod=1. How much do they cost, and do they exploit OpenMP? Bruno -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Jan Stránský proposed the following answer: > -j32 26.1s > -j48 24.51s > -j90 23.27s \ 23.72s > -j92 23.05s \ 23.76s \ 24.24s \ 24.09s > the -j92 or -j90 maybe the optimal jobs pretty much depending on the definition of "optimal". Compared to -j32, -j90 is just 10% faster, but using almost 3x more CPU power. > -j48 1386.40 iter/s > -j90 1279 iter/s > It seems that -j90 is the best. same as above > It looks that ... in the 3D show are different, > I hope to check if the rotation speed matches the falling speed of particles > or not. The direct way is the 3D show. 3D view is just for rough checks. Use "hard numbers" for serious comparisons (like O.bodies[...].state.vel) > if I close the 3D show, the speed of the plank and particles are the same with 3D show open or not? yes (if you mean the simulation-world speed) > If the speed of plank and particles are not depend on the 3D show. simulation state definitely is not influenced by the 3D view (if it was, it would be a bug). > I will storage the bodies' location of the simulation process, and replay the locations after the simulation is over. I would say this is a standard approach > is there a better way to do that? to do what? (storage the bodies' location, replay after the simulation, after the simulation is over, ...) cheers Jan -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 yang yi posted a new comment: Janek Kozicki (cosurgi) , Jan Stránský (honzik) , Bruno Chareyre (bruno-chareyre) Thank you very much for answer my question. According to your suggestion, I checked the server like this (1) Run yade by the command: ~/myYade/install/bin/yade -j90 20200522.py (2) Start the script by the 'start' button on the Controller(), without "3D" show (3) I did 10 iteration test and the time result as follows PC: -j8 39.45s \ 47.79s Server:-j32 26.1s -j48 24.51s -j50 25.32s -j52 24.55s -j60 26.53s -j88 23.29s \ 23.12s -j90 23.27s \ 23.72s -j92 23.05s \ 23.76s \ 24.24s \ 24.09s -j94 23.48s -j96 23.91s Because I get the time by hand, so there is errors. The results seems that the server is faster than PC without 3D show and the -j92 or -j90 maybe the optimal jobs. (4) I used the command : yade --stdperformance -j8 to test the performance But I just to guess the result, I wirte as below -j8 1465.98 iter/s -j48 1386.40 iter/s -j881427 iter/s -j901279 iter/s 1467 iter/s -j921385 iter/s -j961313 iter/s I find the number is unstable. It seems that -j90 is the best. (5) For the above test, I guess that: The before test, I take 3D show, the server is slower than PC very slowly, that is becuase the GUI is depend on just one core of the CPU. For one core of I7-9700k 3.6GH is better than 6146 , 3.2GH. IF my guess is right or not? (6) I have two questions: 1) It looks that the falling speed of particles and the roation speed of the plank in the 3D show are different, if the I modify the number of the particles. So in the Server, I hope to check if the rotation speed matches the falling speed of particles or not. The direct way is the 3D show. However, if 3D show is used, the speed is very very slow. my question is : if I close the 3D show, the speed of the plank and particles are the same with 3D show open or not? 2) If the speed of plank and particles are not depend on the 3D show. I will storage the bodies' location of the simulation process, and replay the locations after the simulation is over. my question : is there a better way to do that? Thank you very much -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Bruno Chareyre posted a new comment: > If the performance is just depend on a core, that is a very terrible message to me Not really. The message was: 1/ of course you don't automatically gain speedup by using more cores, 2/ comparing just a pair of (very different) N gives no real insight on where the optimum is (and there is an optimum, always). So the only solid data at the moment is per-core speed, if it is shocking to hear it could be a way to put the problem a bit differently. :) B. -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Bruno Chareyre proposed the following answer: Ah: and it is absolutely critical that you keep GUI turned *off*. Else the comparisons are meaningless, you could be testing the GPU. You don't use GUI for long simulations anyway. B -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Bruno Chareyre proposed the following answer: > So I use 96 core. Maybe it is a bad idea. Or maybe it is ok but it doesn't give much more compared to, say, 48. OpenMP may have an optimum somewhere and maybe it is 24 cores, or 48 (could well be depending on hardware), or whatever it is. You'll have to find out. I didn't hear about previous tests on 96, that would be interesting to know your results. Cheers Bruno -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Janek Kozicki posted a new comment: Sorry, that was written in a hurry. I mean that you can use these two commands to measure the computer performance using a standardized test. -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Jan Stránský posted a new comment: > But I need a faster speed for the simulation by parallel computation. So I use 96 core. Would another usage of the power be meaningful, e.g. running in parallel 12 simulation, each using -j8? > So I use 96 core. Are you sure there are no other processes running on the computer? How e.g. -j 48 behaves? > If the performance is just depend on a core, that is a very terrible message to me. I did not understand this, but the speed-up depends on the combination of the number of cores used AND the script. There are many factors.. cheers Jan -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Janek Kozicki posted a new comment: run this command: yade --stdperformance -j8 or this command: yade --quickperformance -j8 -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 yang yi posted a new comment: 1. Jan Stránský (honzik) Than you very much for you quickly response. I explain as the follows (1) The script The script must import torch. The code is use to simulated particles falling down with the gravity. #!/usr/bin/env python # encoding: utf-8 ## this programmig is DQN with HMRF-2-NH. from __future__ import print_function # import sys # sys.path.append('~/PycharmProjects/yangyi/yade/Yade20200419_for_Journal of Coal/') # from yadeImport import * import random import math import csv import torch import torch.nn as nn import numpy as np import os import torch.nn.functional as F from torch.distributions import Categorical from yade.gridpfacet import * pi = math.pi Testing = False AddCoalRock = False loadPoint = '00088' o = Omega() o.dt = 1e-12 totalLoss = 0 LastState = [] LastAction = np.zeros((5, 1), dtype=int) saveLoss = [] outputDir = 'Output' checkCounter = 0 numWinds = 5 WinAction = np.zeros((5,1), dtype=int) RewardCoal = 1 RewardRock = -3 nParameters = 2 mu_in = np.zeros((5, nParameters)) sigma_in = np.ones((5, nParameters)) MAP_iter_number = 5 EM_iter = 5 ## === Environment ## widthSpace = 6.8 ## width is the distance from the front coal wall to the back widthHydr = 1.5 lengthSpace = widthHydr * numWinds ## length is the width of 5 windows highCoal = 2 highRock = 2 if AddCoalRock: highCoalRock1 = 1 highCoalRock2 = 1 highCoalRock3 = 1 else: highCoalRock1 = 0 highCoalRock2 = 0 highCoalRock3 = 0 highHydr = 3.8 highUnderground = 10 highBottom = 0.5 highSpace = highUnderground + highHydr + highCoal + highCoalRock1 + highCoalRock2 + highCoalRock3 + highRock radiusCoal = 0.15 radiusRock = 0.15 CheckThick = 1 highDummy = 3 colorCoal = (0, 1, 0) colorRock = (1, 0, 0) colorState = (0, 0, 1) colorReceive = (238/255, 233/255, 191/255) colorShield = (205/255, 150/255, 205/255) colorWind = (0, 1, 1) colorGround = (54/255,54/255, 54/255) angleShield = 50 * 3.1415926 / 180 angleSwingPositive = 15 * 3.1415926 / 180 angleSwingNegtive = 40 * 3.1415926 / 180 lengthShield = 3 lengthTail = 2 windUpperBoundary = 0.9 windLowerBoundary = 0.5019 stateUpperBoundary = highHydr stateLowerBoundary = windLowerBoundary ##———## positionShield = [] positionWind = [] positionTopBeam = [] positionDummy = [] windPosition = np.zeros(5) windPositionPositive = 1 windPositionNegative = 2 shield_y_0 = lengthTail * math.cos(angleShield - angleSwingPositive) shield_y_1 = shield_y_0 + lengthShield * math.cos(angleShield) shield_z_0 = highHydr - lengthShield * math.sin(angleShield) shield_z_1 = highHydr # wind_y_0 = lengthTail * (math.cos(angleShield - angleSwingPositive) - math.cos(angleShield)) wind_y_1 = shield_y_0 wind_z_0 = highHydr - (lengthShield + lengthTail) * math.sin(angleShield) wind_z_1 = highHydr - lengthShield * math.sin(angleShield) topBeam_y_0 = lengthTail * math.cos(angleShield - angleSwingPositive) + lengthShield * math.cos(angleShield) topBean_y_1 = widthSpace # matRock = O.materials.append(JCFpmMat(young=13.5e9, cohesion=2.06e6,density=2487, frictionAngle=radians(10), # tensileStrength=1.13e6, poisson=0.123, jointNormalStiffness=1e8, jointShearStiffness=1e7, jointCohesion=1e6)) HyMat = O.materials.append(FrictMat(frictionAngle=0.1, density=3000, young=2e9)) # matRock = O.materials.append(JCFpmMat(young=13.5e9, cohesion=2.06e6,density=2487, frictionAngle=radians(30), tensileStrength=1.13e1, poisson=0.123, jointNormalStiffness=1e1, jointShearStiffness=1e1, jointCohesion=1e1)) # matCoal = O.materials.append(JCFpmMat(young=4.2e9, cohesion=2.11e6, density=1420, frictionAngle=radians(19.5), # tensileStrength=2.6e6, poisson=0.22, jointNormalStiffness=1e1, jointShearStiffness=1e1, jointCohesion=1e1)) # matRock = O.materials.append(FrictMat(frictionAngle=radians(30), density=2487, young=13.5e9)) matCoal = O.materials.append(FrictMat(frictionAngle=radians(29.5), density=1420, young=4.2e9)) myGraviaty = -1200 nIterControl = 1000 nCheckEnd = 3000 nIterReload =1 VelocityWindPositive = 40 VelocityWindNegative = 60 percentCoalStopEpisode = 20 # matGround = O.materials.append(CohFrictMat(young=E, poisson=0.3, density=2650, frictionAngle=radians(30), normalCohesion=3e100, # shearCohesion=3e100, momentRotationLaw=True)) def Boundary(): boundary = O.bodies.append(geom.facetBox((lengthSpace / 2, widthSpace / 2, highSpace / 2 - highUnderground), (lengthSpace / 2, widthSpace / 2, highSpace / 2), wallMask=63, material =HyMat )) def Ground(): O.bodies.append(utils.wall(position=-highUnderground, sense=0, axis=2, color=colorGround, material=-1)) def Dummy(): for i in range (1, numWinds): temp=[ Vector3(widthHydr*i, 0 , -highUnderground), Vector3(widthHydr*i, widthSpace
Re: [Yade-users] [Question #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Janek Kozicki posted a new comment: If you have a recent yade version you can do yade --stdperformance -jN benchmark, with same N on both systems. If the speed is not stable, because some different programs are running it will take a long time, so you can use --quickperformance instead. -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Bruno Chareyre proposed the following answer: Hi, What you observe is actually expected: XEON 4, 3.2GH I7 3.6GH The I7 is faster. HPC rarely outperform personal computers in per-core performance. Arguably, you use "-jSomething", but it makes no sense to discuss -jAnything on the basis of just an obscure script name "20200522.py". You did not mention how -j2 compares to -j1 on any of the procs, so that would be just blind guessing to try and answer this part. Compare -j1 on both first. Bruno -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Son Pham Thai proposed the following answer: Hi, i have also used remote desktop PC to run yade. You should be very clear on which one you think that it is slow: (1). YADE simulation (running in the command window, i.e. the terminal) or (2). 3D visualization in YADE GUI ? I guess it is (2) since (2) depends on the connection between you and the remote controlled computer, not the hardware of your PC or the remote controlled computer. Hope that help, -- 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 #690973]: running on a server is slower than on a PC
Question #690973 on Yade changed: https://answers.launchpad.net/yade/+question/690973 Status: Open => Answered Jan Stránský proposed the following answer: Hello, TLTR: do not compare -j8 and -j96, compare -j8 for both systems. Difference of -j8 and -j96 is another problem not much related to different hardware. Long answer: to answer / give you some hints, we need more information, e.g. the script you are running. > I open the yade simulation, show 3D how it behaves without any GUI? > The speed ... is slower ... it is very very obviously. please be more specific what "very obviously" means. 10% slower ? 3x slower? 1000x slower? > On the server ... -j96 > On the PC ... -j8 what are the results if you use e.g. -j 4 (or the same -j) for both systems? In general, it is not very good idea to compare -j 8 and -j 96, it is then very different situation, very much depending on the simulation itself.. cheers Jan -- 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