Question #692681 on Yade changed:
https://answers.launchpad.net/yade/+question/692681
Status: Needs information => Open
Luc OGER gave more information on the question:
here the cmake command
and the py code
#Result indeterminism
#It is naturally expected that running the same simulation several times will
give exactly the same results: although the computation is done
#with finite precision, round-off errors would be deterministically the same at
every run. While this is true for single-threaded computation
#where exact order of all operations is given by the simulation itself, it is
not true anymore in multi-threaded computation which is described in detail in
later sections.
#The straight-forward manner of parallel processing in explicit DEM is given by
the possibility of treating interactions in arbitrary order.
#Strain and stress is evaluated for each interaction independently, but forces
from interactions have to be summed up. If summation order is also arbitrary
#(in Yade, forces are accumulated for each thread in the order interactions are
processed, then summed together), then the results can be slightly different.
For instance
#(1/10.)+(1/13.)+(1/17.)=0.23574660633484162
#(1/17.)+(1/13.)+(1/10.)=0.23574660633484165
#As forces generated by interactions are assigned to bodies in quasi-random
order, summary force Fi
#on the body can be different between single-threaded and multi-threaded
computations, but also between different runs of multi-threaded computation
with exactly the same parameters.
#Exact thread scheduling by the kernel is not predictable since it depends on
asynchronous events (hardware interrupts) and other unrelated tasks running on
the system;
#and it is thread scheduling that ultimately determines summation order of
force contributions from interactions.
# The components of the batch are:
# 1. table with parameters, one set of parameters per line (ccc.table)
# 2. readParamsFromTable which reads respective line from the parameter file
# 3. the simulation muse be run using yade-batch, not yade
#
# $ yade-batch --job-threads=1 03-oedometric-test.table 03-oedometric-test.py
#
# load parameters from file if run in batch
# default values are used if not run from batch
# gravity deposition in box, showing how to plot and save history of data,
# and how to control the simulation while it is running by calling
# python functions from within the simulation loop
#pas_box theta_max converg_min cover_pack_fraction init_seed friction ratio
#model_type bottom_cover pas_box theta_max converg_min cover_pack_fraction
init_seed friction ratio
#.1 55. .002 0.1 210 0.4 4
readParamsFromTable(model_type=1, packing_fraction=0.5,pas_box=0.5,
theta_max=5.0, nb_cycles=3,converg_min=0.5,nb_layers=10,init_seed=10,
friction=0.15,ratio=1)
# make rMean, rRelFuzz, maxLoad accessible directly as variables later
from yade.params.table import *
# import yade modules that we will use below
from yade import pack, plot, export,math
global ratio,nombre,position_prec,position_init # size ratio between the glued
spheres and the moving ones
global converg_min, init_seed,nombre_moving,z_max # coverage percent for moving
spheres
global i_pas,
box_size,pas_box,rayon,step0,step1,step2,step_precedent,gravity_y,gravity_z,theta_max,theta_max,nom_file,filename_yade,traitement_file,str_Angle,
nb_cycles,numero_cycle,num_Angle
#some parameters passed by batch_table:
batch : friction= 0.5
batch : theta_max = 30.0
batch : pas_box = 0.1
batch : ratio = 3 # size ratio between the glued spheres and the moving
ones
batch : cover_pack_fraction = 0.2 # coverage percent for moving spheres
batch : init_seed=10
batch : packing_fraction = 70./100.
batch : model_type = 1
#some parameters:
shear_modulus = 1e5
poisson_ratio = 0.3
young_modulus = 2*shear_modulus*(1+poisson_ratio)
local_damping = 0.01
viscous_normal = 0.021
viscous_shear = 0.8*viscous_normal
angle = math.atan(friction)
# initialisation coordonnees initiales
#newTable("position_init",600,4) # Create a new table with 5 rows and 3 column
#creating a material (FrictMat):
id_SphereMat=O.materials.append(FrictMat(young=young_modulus,poisson=poisson_ratio,density=2500,frictionAngle=angle,label="glass_beads"))
SphereMat=O.materials[id_SphereMat]
box_size = 1.0
i_pas = 0
step0=0
mask1=0b01
num_Angle= pas_box*i_pas
gravity_y = 9.81*sin( num_Angle*3.14/180.0)
gravity_z = 9.81*cos( num_Angle*3.14/180.0)
O.reset
nom_file=str(model_type)+"_"+str(packing_fraction)+"_"+str(theta_max)+"_"+str(nb_cycles)+"_"+str(nb_layers)+"_"+str(ratio)+'_'+str(friction)+'_'+str(pas_box)+'_'+str(converg_min)+'_'+str(init_seed)
filename_yade=nom_file+'.yade'
rayon = 0.025
height = 5.0*rayon*nb_layers
# create rectangular box from facets
O.bodies.append(geom.facetBox((box_size/2.0,box_size/2.0,height),(box_size/2.0,box_size/2.0,height),wallMask=31))
# create empty sphere packing
