def do_integration():
cfg = swarmng.config(nsys=64,
nbod=3,
log_writer='bdb',
log_output_db=output_file_name,
log_interval=1,
integrator='hermite_cpu_log',
time_step=0.01,
nogpu=1)
ref = swarmng.generate_ensemble(cfg)
ens = ref.clone()
swarmng.init(cfg)
integ = swarmng.Integrator.create(cfg)
integ.ensemble = ens
swarmng.sync
for i in range(1, final_time + 1):
integ.destination_time = i
integ.integrate()
def do_integration():
cfg = swarmng.config(
nsys=64,
nbod=3,
log_writer='bdb',
log_output_db=output_file_name,
log_interval=1,
integrator='hermite_cpu_log',
time_step=0.01,
nogpu=1
);
ref = swarmng.generate_ensemble( cfg )
ens = ref.clone()
swarmng.init(cfg)
integ = swarmng.Integrator.create( cfg )
integ.ensemble = ens
swarmng.sync
for i in range(1,final_time+1):
integ.destination_time = i
integ.integrate()
#
# Source code for this tutorial can be found at @ref py/tutorial.py
#
# First thing is to import swarmng package. It is located in `\<SOURCE DIRECTORY\>/py/swarmng/`
# It takes care of loading the libswarmng_ext.so; it also contains some Pythonified
# API on top of libswarmng_ext. But please run the scripts
# from your build directory so swarmng can find your libraries.
import swarmng
import os
# swarm functions cannot take hashes for config. So
# we have to create the special config object (a C++ std::map)
# using swarmng.config function
# This first line initializes Swarm-NG. 'nogpu' option
# allows us to run this script on a machine without GPU
swarmng.init(swarmng.config(nogpu=1))
# Now we can load an ensemble from a text file. The ensemble file is in the swarm source directory:
ensemble_filename = os.path.join(swarmng.SWARMDIR,
'test/integrators/test.3.in.txt')
# We use a simple call that loads the file and returns the data structure
ref = swarmng.DefaultEnsemble.load_from_text(ensemble_filename)
# We can also look into the data structure and view the values
for s in ref:
print("System {0}, time: {1}, state: {2} ".format(s.id, s.time, s.state))
for i, b in enumerate(s):
print("\tBody {0} pos: {1}\tvel:{2}".format(i, b.pos, b.vel))
# We can treat the data structure as an array. e.g to set the position
# of body 0 of system 3 you can write:
#!/usr/bin/env python2
# -*- coding: utf8 -*-
import swarmng
import time
for c in range(0,2):
swarmng.init(swarmng.config(CUDA_DEVICE=c,verbose=1))
integ = swarmng.Integrator.create(swarmng.config(integrator="hermite",time_step=0.001))
times = []
for nb in range(3,7):
integ.ensemble = swarmng.generate_ensemble(swarmng.config(nsys=8000,nbod=nb))
integ.destination_time = 10.0
start = time.clock()
integ.integrate()
times.append(time.clock() - start)
print(times)
# The first step is to import the swarmng module. We also use make_test_case from the
# @ref TutorialPythonEnsemble "Ensemble generation tutorial" to generate our test case.
import swarmng
import random
from ensemble_tutorial import make_test_case
# \subsection candi Configuration and initial conditions
# RMAX is the maximum radius of the planetary system. If the planets is farther than RMAX from
# the origin, we consider it ejected.
RMAX = 10
#
# Configuratino for the integration, we use CPU version of the PEC² Hermite integrator, it is
# by default checks for ejections when the planets get too far from the origin.
cfg = swarmng.config(
integrator = "hermite_cpu",
time_step = 1e-3,
nogpu = 1,
deactivate_on_ejection = 1,
rmax = RMAX
)
# We have to set the destination_time directly on the integrator object
# and it cannot be included in the Config object.
destination_time = 100
#
# We create an ensemble with very close orbits. This ensures that the planets
# will come close at some point and the result would be an ejection.
ens = make_test_case(nsys=20, nbod = 6, spacing_factor=1.01);
#
# \section int Integration
# Same procedure as in @ref TutorialPython. Set-up the integrator parameters and
# call the method @ref swarmng.Integrator.integrate "integrate".
swarmng.init(cfg)
import swarmng, argparse
import os
swarmng.init(swarmng.config(nogpu=0))
ensemble_file = os.path.join(swarmng.SWARMDIR,
'test/integrators/test.3.in.txt')
ref = swarmng.DefaultEnsemble.load_from_text(ensemble_file)
ens = ref.clone()
integrator_cfg = swarmng.config(integrator='irk2', time_step=.001, nbod=3)
integ = swarmng.Integrator.create(integrator_cfg)
integ.ensemble = ens
integ.destination_time = 100
integ.integrate()
ens.save_to_text("hermite_cpu_snapshot.txt")
max_deltaE = swarmng.find_max_energy_conservation_error(ens, ref)
print("Max energy conservation error %g" % max_deltaE)
#
# The first step is to import the swarmng module. We also use make_test_case from the
# @ref TutorialPythonEnsemble "Ensemble generation tutorial" to generate our test case.
import swarmng
import random
from ensemble_tutorial import make_test_case
# \subsection candi Configuration and initial conditions
# RMAX is the maximum radius of the planetary system. If the planets is farther than RMAX from
# the origin, we consider it ejected.
RMAX = 10
#
# Configuratino for the integration, we use CPU version of the PEC² Hermite integrator, it is
# by default checks for ejections when the planets get too far from the origin.
cfg = swarmng.config(integrator="hermite_cpu",
time_step=1e-3,
nogpu=1,
deactivate_on_ejection=1,
rmax=RMAX)
# We have to set the destination_time directly on the integrator object
# and it cannot be included in the Config object.
destination_time = 100
#
# We create an ensemble with very close orbits. This ensures that the planets
# will come close at some point and the result would be an ejection.
ens = make_test_case(nsys=20, nbod=6, spacing_factor=1.01)
#
# \section int Integration
# Same procedure as in @ref TutorialPython. Set-up the integrator parameters and
# call the method @ref swarmng.Integrator.integrate "integrate".
swarmng.init(cfg)
integ = swarmng.Integrator.create(cfg)
#
# Source code for this tutorial can be found at @ref py/tutorial.py
#
# First thing is to import swarmng package. It is located in `\<SOURCE DIRECTORY\>/py/swarmng/`
# It takes care of loading the libswarmng_ext.so; it also contains some Pythonified
# API on top of libswarmng_ext. But please run the scripts
# from your build directory so swarmng can find your libraries.
import swarmng
import os
# swarm functions cannot take hashes for config. So
# we have to create the special config object (a C++ std::map)
# using swarmng.config function
# This first line initializes Swarm-NG. 'nogpu' option
# allows us to run this script on a machine without GPU
swarmng.init(swarmng.config(nogpu=1))
# Now we can load an ensemble from a text file. The ensemble file is in the swarm source directory:
ensemble_filename = os.path.join(swarmng.SWARMDIR , 'test/integrators/test.3.in.txt')
# We use a simple call that loads the file and returns the data structure
ref = swarmng.DefaultEnsemble.load_from_text( ensemble_filename )
# We can also look into the data structure and view the values
for s in ref:
print("System {0}, time: {1}, state: {2} ".format(s.id, s.time, s.state))
for i,b in enumerate(s):
print("\tBody {0} pos: {1}\tvel:{2}".format(i,b.pos,b.vel))
# We can treat the data structure as an array. e.g to set the position
# of body 0 of system 3 you can write:
import swarmng, argparse
import os
swarmng.init(swarmng.config(nogpu=0))
ensemble_file = os.path.join(swarmng.SWARMDIR,'test/integrators/test.3.in.txt')
ref = swarmng.DefaultEnsemble.load_from_text(ensemble_file)
ens = ref.clone()
integrator_cfg = swarmng.config(
integrator = 'irk2',
time_step = .001,
nbod = 3
)
integ = swarmng.Integrator.create(integrator_cfg)
integ.ensemble = ens
integ.destination_time = 100
integ.integrate()
ens.save_to_text("hermite_cpu_snapshot.txt")
max_deltaE = swarmng.find_max_energy_conservation_error(ens,ref)
print("Max energy conservation error %g" % max_deltaE)