def test16(self): convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 149.5e6 | units.km) smalln = SmallN(convert_nbody) smalln.initialize_code() smalln.dt_dia = 5000 stars = self.new_system_of_sun_and_earth() moon = datamodel.Particle() moon.mass = units.kg(7.3477e22) moon.radius = units.km(1737.10) moon.position = units.km(numpy.array((149.5e6 + 384.399 ,0.0,0.0))) moon.velocity = units.ms(numpy.array((0.0,29800 + 1022,0.0))) stars.add_particle(moon) earth = stars[1] smalln.particles.add_particles(stars) smalln.evolve_model(365.0 | units.day) smalln.update_particle_tree() smalln.update_particle_set() self.assertEquals(len(smalln.particles), 5) self.assertEarthAndMoonWasDetectedAsBinary(smalln.particles, stars) inmemory = smalln.particles.copy() self.assertEarthAndMoonWasDetectedAsBinary(inmemory, stars) test_results_path = self.get_path_to_results() output_file = os.path.join(test_results_path, "newsmalln-test16.hdf5") if os.path.exists(output_file): os.remove(output_file) io.write_set_to_file(smalln.particles, output_file, "hdf5") fromfile = io.read_set_from_file(output_file, "hdf5") self.assertEarthAndMoonWasDetectedAsBinary(fromfile, stars)
def test16(self): convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 149.5e6 | units.km) smalln = SmallN(convert_nbody) smalln.initialize_code() smalln.dt_dia = 5000 stars = self.new_system_of_sun_and_earth() moon = datamodel.Particle() moon.mass = units.kg(7.3477e22) moon.radius = units.km(1737.10) moon.position = units.km(numpy.array((149.5e6 + 384.399, 0.0, 0.0))) moon.velocity = units.ms(numpy.array((0.0, 29800 + 1022, 0.0))) stars.add_particle(moon) earth = stars[1] smalln.particles.add_particles(stars) smalln.evolve_model(365.0 | units.day) smalln.update_particle_tree() smalln.update_particle_set() self.assertEqual(len(smalln.particles), 5) self.assertEarthAndMoonWasDetectedAsBinary(smalln.particles, stars) inmemory = smalln.particles.copy() self.assertEarthAndMoonWasDetectedAsBinary(inmemory, stars) test_results_path = self.get_path_to_results() output_file = os.path.join(test_results_path, "newsmalln-test16.hdf5") if os.path.exists(output_file): os.remove(output_file) io.write_set_to_file(smalln.particles, output_file, "hdf5") fromfile = io.read_set_from_file(output_file, "hdf5") self.assertEarthAndMoonWasDetectedAsBinary(fromfile, stars) smalln.stop()
def run_smallN( particles, end_time = 1000 | nbody_system.time, delta_t = 10 | nbody_system.time, accuracy_parameter = 0.1 ): gravity = SmallN(redirection = "none") # , debugger="gdb") gravity.initialize_code() gravity.parameters.set_defaults() gravity.parameters.timestep_parameter = accuracy_parameter gravity.parameters.cm_index = 2001 gravity.commit_parameters() time = 0 | nbody_system.time print "\nadding particles to smallN" sys.stdout.flush() gravity.set_time(time); gravity.particles.add_particles(particles) print "committing particles to smallN" gravity.commit_particles() print "smallN: number_of_stars =", len(particles) print "smallN: evolving to time =", end_time.number, print "in steps of", delta_t.number sys.stdout.flush() E0 = print_log('smallN', gravity) # Channel to copy values from the code to the set in memory. channel = gravity.particles.new_channel_to(particles) while time < end_time: time += delta_t print 'evolving smallN to time', time.number sys.stdout.flush() gravity.evolve_model(time) print_log('smallN', gravity, E0) over = gravity.is_over() if over.number: print 'interaction is over\n'; sys.stdout.flush() # Create a tree in the module representing the binary structure. gravity.update_particle_tree() # Return the tree structure to AMUSE. Children are # identified by get_children_of_particle in interface.??, # and the information is returned in the copy operation. gravity.update_particle_set() gravity.particles.synchronize_to(particles) channel.copy() channel.copy_attribute("index_in_code", "id") gravity.stop() # Basic diagnostics: BinaryTreesOnAParticleSet creates # binary tree structure for all particles in the set; then # we loop over roots (top-level nodes) and print data on # all binaries below each. print "smallN binaries:"; sys.stdout.flush() x = trees.BinaryTreesOnAParticleSet(particles, "child1", "child2") roots = list(x.iter_roots()) for r in roots: for level, particle in r.iter_levels(): print ' '*level, int(particle.id.number), if not particle.child1 is None: M,a,e,r,E = get_cm_binary_elements(particle) print " mass = %.5e" % (M.number) m1 = particle.child1.mass m2 = particle.child2.mass print_elements(' ', a, e, r, E*m1*m2/M) else: print '' sys.stdout.flush() return E0 sys.stdout.flush() gravity.stop() raise Exception("Did not finish the small-N simulation " +"before end time {0}".format(end_time))
def run_smallN(particles, end_time=1000 | nbody_system.time, delta_t=10 | nbody_system.time, accuracy_parameter=0.1): gravity = SmallN(redirection="none") # , debugger="gdb") gravity.initialize_code() gravity.parameters.set_defaults() gravity.parameters.timestep_parameter = accuracy_parameter gravity.parameters.cm_index = 2001 gravity.commit_parameters() time = 0 | nbody_system.time print("\nadding particles to smallN") sys.stdout.flush() gravity.set_time(time) gravity.particles.add_particles(particles) print("committing particles to smallN") gravity.commit_particles() print("smallN: number_of_stars =", len(particles)) print("smallN: evolving to time =", end_time.number, end=' ') print("in steps of", delta_t.number) sys.stdout.flush() E0 = print_log('smallN', gravity) # Channel to copy values from the code to the set in memory. channel = gravity.particles.new_channel_to(particles) while time < end_time: time += delta_t print('evolving smallN to time', time.number) sys.stdout.flush() gravity.evolve_model(time) print_log('smallN', gravity, E0) over = gravity.is_over() if over.number: print('interaction is over\n') sys.stdout.flush() # Create a tree in the module representing the binary structure. gravity.update_particle_tree() # Return the tree structure to AMUSE. Children are # identified by get_children_of_particle in interface.??, # and the information is returned in the copy operation. gravity.update_particle_set() gravity.particles.synchronize_to(particles) channel.copy() channel.copy_attribute("index_in_code", "id") gravity.stop() # Basic diagnostics: BinaryTreesOnAParticleSet creates # binary tree structure for all particles in the set; then # we loop over roots (top-level nodes) and print data on # all binaries below each. print("smallN binaries:") sys.stdout.flush() x = trees.BinaryTreesOnAParticleSet(particles, "child1", "child2") roots = list(x.iter_roots()) for r in roots: for level, particle in r.iter_levels(): print(' ' * level, int(particle.id.number), end=' ') if not particle.child1 is None: M, a, e, r, E = get_cm_binary_elements(particle) print(" mass = %.5e" % (M.number)) m1 = particle.child1.mass m2 = particle.child2.mass print_elements(' ', a, e, r, E * m1 * m2 / M) else: print('') sys.stdout.flush() return E0 sys.stdout.flush() gravity.stop() raise Exception("Did not finish the small-N simulation " + "before end time {0}".format(end_time))
def run_collision(GravitatingBodies, end_time, delta_time, save_file, **kwargs): # Define Additional User Options and Set Defaults Properly converter = kwargs.get("converter", None) doEncPatching = kwargs.get("doEncPatching", False) doVerboseSaves = kwargs.get("doVerboseSaves", False) if converter == None: converter = nbody_system.nbody_to_si(GravitatingBodies.mass.sum(), 2 * np.max(GravitatingBodies.radius.number) | GravitatingBodies.radius.unit) # Storing Initial Center of Mass Information for the Encounter rCM_i = GravitatingBodies.center_of_mass() vCM_i = GravitatingBodies.center_of_mass_velocity() # Fixing Stored Encounter Particle Set to Feed into SmallN GravitatingBodies = Particles(particles=GravitatingBodies) if 'child1' in GravitatingBodies.get_attribute_names_defined_in_store(): del GravitatingBodies.child1, GravitatingBodies.child2 # Moving the Encounter's Center of Mass to the Origin and Setting it at Rest GravitatingBodies.position -= rCM_i GravitatingBodies.velocity -= vCM_i # Setting Up Gravity Code gravity = SmallN(redirection = 'none', convert_nbody = converter) gravity.initialize_code() gravity.parameters.set_defaults() gravity.parameters.allow_full_unperturbed = 0 gravity.particles.add_particles(GravitatingBodies) # adds bodies to gravity calculations gravity.commit_particles() channel_from_grav_to_python = gravity.particles.new_channel_to(GravitatingBodies) channel_from_grav_to_python.copy() # Setting Coarse Timesteps list_of_times = np.arange(0. | units.yr, end_time, delta_time) stepNumber = 0 # Integrate the Encounter Until Over ... for current_time in list_of_times: # Evolve the Model to the Desired Current Time gravity.evolve_model(current_time) # Update Python Set in In-Code Set channel_from_grav_to_python.copy() # original channel_from_grav_to_python.copy_attribute("index_in_code", "id") # Handle Writing Output of Integration if doVerboseSaves: # Write a Save Every Coarse Timestep write_set_to_file(GravitatingBodies.savepoint(current_time), save_file, 'hdf5') else: # Write a Save at the Begninning, Middle & End Times if stepNumber==0 or stepNumber==len(list_of_times) or stepNumber==len(list_of_times)/2: # Write Set to File write_set_to_file(GravitatingBodies.savepoint(current_time), save_file, 'hdf5') # Check to See if the Encounter is Declared "Over" Every 50 Timesteps if stepNumber%50: over = gravity.is_over() if over: gravity.update_particle_tree() gravity.update_particle_set() gravity.particles.synchronize_to(GravitatingBodies) channel_from_grav_to_python.copy() print "Encounter has finished at Step #", stepNumber break else: print "Encounter has NOT finished at Step #", stepNumber stepNumber +=1 # Stop the Gravity Code Once the Encounter Finishes gravity.stop() # Seperate out the Systems to Prepare for Encounter Patching if doEncPatching: ResultingPSystems = stellar_systems.get_planetary_systems_from_set(GravitatingBodies, converter=converter, RelativePosition=True) else: ResultingPSystems = stellar_systems.get_planetary_systems_from_set(GravitatingBodies, converter=converter, RelativePosition=False) return ResultingPSystems