def pre_step(self, step, level_number):
"""
Default routine called before each step
Args:
step: the current step
level_number: the current level number
"""
super(error_output, self).pre_step(step, level_number)
L = step.levels[level_number]
# This is a bit black magic: we are going to run pySDC within the hook to check the error against the "exact"
# solution of the collocation problem
description = step.params.description
description['level_params']['restol'] = 1E-14
description['problem_params']['direct_solver'] = True
controller_params = step.params.controller_params
del controller_params[
'hook_class'] # get rid of the hook, otherwise this will be an endless recursion..
controller_params['use_iteration_estimator'] = False
controller_params['logger_level'] = 90
controller = controller_nonMPI(num_procs=1,
description=description,
controller_params=controller_params)
self.uex, _ = controller.run(u0=L.u[0], t0=L.time, Tend=L.time + L.dt)
def main():
"""
A simple test program to setup a full multi-step multi-level hierarchy
"""
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-10
level_params['dt'] = 0.5
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = [3]
# initialize problem parameters
problem_params = dict()
problem_params['nu'] = 0.1 # diffusion coefficient
problem_params['freq'] = 4 # frequency for the test value
problem_params['nvars'] = [31, 15, 7
] # number of degrees of freedom for each level
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 20
# initialize space transfer parameters
space_transfer_params = dict()
space_transfer_params['rorder'] = 2
space_transfer_params['iorder'] = 6
# fill description dictionary for easy step instantiation
description = dict()
description['problem_class'] = heat1d_forced # pass problem class
description['problem_params'] = problem_params # pass problem parameters
description['sweeper_class'] = imex_1st_order # pass sweeper (see part B)
description['sweeper_params'] = sweeper_params # pass sweeper parameters
description['level_params'] = level_params # pass level parameters
description['step_params'] = step_params # pass step parameters
description[
'space_transfer_class'] = mesh_to_mesh # pass spatial transfer class
description[
'space_transfer_params'] = space_transfer_params # pass paramters for spatial transfer
# instantiate controller
controller = controller_nonMPI(num_procs=10,
controller_params={},
description=description)
# check number of levels
f = open('step_5_A_out.txt', 'w')
for i in range(len(controller.MS)):
out = "Process %2i has %2i levels" % (i, len(controller.MS[i].levels))
f.write(out + '\n')
print(out)
f.close()
assert all([len(S.levels) == 3 for S in controller.MS
]), "ERROR: not all steps have the same number of levels"
def run_reference(Tend):
"""
Routine to run particular SDC variant
Args:
Tend (float): end time for dumping
"""
# load (incomplete) default parameters
description, controller_params = setup_parameters_FFT()
# setup parameters "in time"
t0 = 0
# instantiate controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# filter statistics by variant (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(niters)
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (float(
np.std(niters)), float(np.var(niters)))
print(out)
timing = sort_stats(filter_stats(stats, type='timing_run'), sortby='time')
print('Time to solution: %6.4f sec.' % timing[0][1])
print()
computed_radii_tmp = sort_stats(filter_stats(stats,
type='computed_radius'),
sortby='time')
computed_radii = np.array([item0[1] for item0 in computed_radii_tmp])
print(len(computed_radii_tmp), len(computed_radii))
fname = 'data/AC_reference_FFT_Tend{:.1e}'.format(Tend)
np.savez_compressed(file=fname, uend=uend.values, radius=computed_radii)
def main():
"""
Van der Pol's oscillator reference solution
"""
# set time parameters
t0 = 0.0
Tend = 10.0
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-12
level_params['dt'] = (Tend - t0) / 2000.0
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = 5
sweeper_params['QI'] = 'IE'
# initialize problem parameters
problem_params = dict()
problem_params['newton_tol'] = 1E-14
problem_params['newton_maxiter'] = 50
problem_params['mu'] = 10
problem_params['u0'] = (2.0, 0)
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 50
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 20
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = vanderpol
description['problem_params'] = problem_params
description['sweeper_class'] = generic_implicit
description['sweeper_params'] = sweeper_params
description['level_params'] = level_params
description['step_params'] = step_params
# instantiate the controller
controller_ref = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller_ref.MS[0].levels[0].prob
uinit = P.u_exact(t0)
uend_ref, stats_ref = controller_ref.run(u0=uinit, t0=t0, Tend=Tend)
np.save('data/vdp_ref.npy', uend_ref.values)
def run_faulty_simulations(type=None, niters=None, cwd=''):
"""
A simple program to run faulty simulations
Args:
type (str): setup type
niters (int): number of iterations in clean run
f: file handler
cwd (str): current workind directory
"""
if type == 'diffusion':
description, controller_params = diffusion_setup()
elif type == 'reaction':
description, controller_params = reaction_setup()
elif type == 'vanderpol':
description, controller_params = vanderpol_setup()
else:
raise ValueError('No valid setup type provided, aborting..')
# set time parameters
t0 = 0.0
Tend = description['level_params']['dt']
filehandle_injections = open(cwd + 'data/dump_injections_' + type + '.txt',
'w')
controller_params['hook_class'] = fault_hook
description['sweeper_params']['allow_fault_correction'] = True
description['sweeper_params'][
'dump_injections_filehandle'] = filehandle_injections
description['sweeper_params']['niters'] = niters
# instantiate controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# number of runs
nruns = 500
results = []
for nr in range(nruns):
# this is where the iteration is happening
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
results.append(stats)
filehandle_injections.close()
dill.dump(results, open(cwd + "data/results_" + type + ".pkl", "wb"))
def main():
"""
A simple test program to demonstrate residual visualization
"""
# get parameters from Step 6, Part A
description, controller_params, t0, Tend = set_parameters_ml()
# use 8 processes here
num_proc = 8
# instantiate controller
controller = controller_nonMPI(num_procs=num_proc,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# compute exact solution and compare (for testing purposes only)
uex = P.u_exact(Tend)
err = abs(uex - uend)
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
min_iter = 99
max_iter = 0
f = open('step_8_A_out.txt', 'w')
for item in iter_counts:
out = 'Number of iterations for time %4.2f: %1i' % item
f.write(out + '\n')
print(out)
min_iter = min(min_iter, item[1])
max_iter = max(max_iter, item[1])
f.close()
# call helper routine to produce residual plot
fname = 'step_8_residuals.png'
show_residual_across_simulation(stats=stats, fname=fname)
assert err < 6.1555e-05, 'ERROR: error is too large, got %s' % err
assert os.path.isfile(fname), 'ERROR: residual plot has not been created'
assert min_iter == 8 and max_iter == 8, "ERROR: number of iterations not as expected, got %s and %s" % \
(min_iter, max_iter)
def main(dt, Tend):
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-08
level_params['dt'] = dt
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussLobatto
sweeper_params['num_nodes'] = 3
# initialize problem parameters for the Penning trap
problem_params = dict()
problem_params['delta'] = 1
problem_params['a0'] = 0.07
problem_params['u0'] = np.array([[0, -1, 0], [0.05, 0.01, 0], [1], [1]])
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 20
# initialize controller parameters
controller_params = dict()
controller_params['hook_class'] = particles_output # specialized hook class for more statistics and output
controller_params['logger_level'] = 30
# controller_params['log_to_file'] = True
# controller_params['fname'] = 'step_3_B_out.txt'
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = planewave_single
description['problem_params'] = problem_params
description['sweeper_class'] = boris_2nd_order
description['sweeper_params'] = sweeper_params
description['level_params'] = level_params
# description['space_transfer_class'] = particles_to_particles # this is only needed for more than 2 levels
description['step_params'] = step_params
# instantiate the controller (no controller parameters used here)
controller = controller_nonMPI(num_procs=1, controller_params=controller_params, description=description)
# set time parameters
t0 = 0.0
Tend = Tend
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_init()
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
return uinit, stats, problem_params['a0']
def run_simulation():
"""
A simple test program to run IMEX SDC for a single time step
"""
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-10
level_params['dt'] = 0.1
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = 3
# initialize problem parameters
problem_params = dict()
problem_params['nu'] = 0.1 # diffusion coefficient
problem_params['freq'] = 4 # frequency for the test value
problem_params['nvars'] = 1023 # number of degrees of freedom
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 20
# initialize controller parameters (<-- this is new!)
controller_params = dict()
controller_params['logger_level'] = 30 # reduce verbosity of each run
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = heat1d_forced
description['problem_params'] = problem_params
description['sweeper_class'] = imex_1st_order
description['sweeper_params'] = sweeper_params
description['level_params'] = level_params
description['step_params'] = step_params
# instantiate the controller (no controller parameters used here)
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# set time parameters
t0 = 0.1
Tend = 0.9
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
return stats
def main():
"""
Van der Pol's oscillator inc. visualization
"""
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-10
level_params['dt'] = 0.1
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = 3
sweeper_params['QI'] = 'LU'
# initialize problem parameters
problem_params = dict()
problem_params['newton_tol'] = 1E-12
problem_params['newton_maxiter'] = 50
problem_params['mu'] = 5
problem_params['u0'] = (1.0, 0)
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 20
# initialize controller parameters
controller_params = dict()
controller_params['hook_class'] = trajectories
controller_params['logger_level'] = 30
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = vanderpol
description['problem_params'] = problem_params
description['sweeper_class'] = generic_implicit
description['sweeper_params'] = sweeper_params
description['level_params'] = level_params
description['step_params'] = step_params
# instantiate the controller
controller = controller_nonMPI(num_procs=1, controller_params=controller_params, description=description)
# set time parameters
t0 = 0.0
Tend = 20.0
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
def run_clean_simulations(type=None):
"""
A simple code to run fault-free simulations
Args:
type (str): setup type
f: file handler
"""
if type == 'diffusion':
description, controller_params = diffusion_setup()
elif type == 'reaction':
description, controller_params = reaction_setup()
elif type == 'vanderpol':
description, controller_params = vanderpol_setup()
else:
raise ValueError('No valid setup type provided, aborting..')
# set time parameters
t0 = 0.0
Tend = description['level_params']['dt']
# instantiate controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# this is where the iteration is happening
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# print('This clean run took %s iterations!' % iter_counts[0][1])
return iter_counts[0][1]
def run_SDC_variant(variant=None, inexact=False):
"""
Routine to run particular SDC variant
Args:
variant (str): string describing the variant
inexact (bool): flag to use inexact nonlinear solve (or nor)
Returns:
results and statistics of the run
"""
# load (incomplete) default parameters
description, controller_params = setup_parameters()
# add stuff based on variant
if variant == 'explicit':
description['problem_class'] = allencahn_front_fullyimplicit
description['sweeper_class'] = explicit
else:
raise NotImplemented('Wrong variant specified, got %s' % variant)
# setup parameters "in time"
t0 = 0
Tend = 1.0 / (16.0 * 128.0**2)
# instantiate controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
# uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
wrapped = wrapper(controller.run, u0=uinit, t0=t0, Tend=Tend)
print(timeit.timeit(wrapped, number=10000) / 10000.0)
def pre_step(self, step, level_number):
"""
Default routine called before each step
Args:
step: the current step
level_number: the current level number
"""
super(error_output, self).pre_step(step, level_number)
L = step.levels[level_number]
description = step.params.description
description['level_params']['restol'] = 1E-14
description['problem_params']['direct_solver'] = True
controller_params = step.params.controller_params
del controller_params['hook_class']
controller_params['use_iteration_estimator'] = False
controller_params['logger_level'] = 90
controller = controller_nonMPI(num_procs=1, description=description, controller_params=controller_params)
self.uex, _ = controller.run(u0=L.u[0], t0=L.time, Tend=L.time + L.dt)
def main():
"""
A simple test program to do compare PFASST with multi-step SDC
"""
# initialize level parameters
level_params = dict()
level_params['restol'] = 5E-10
level_params['dt'] = 0.125
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = [3]
# initialize problem parameters
problem_params = dict()
problem_params['nu'] = 0.1 # diffusion coefficient
problem_params['freq'] = 2 # frequency for the test value
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 50
# initialize space transfer parameters
space_transfer_params = dict()
space_transfer_params['rorder'] = 2
space_transfer_params['iorder'] = 6
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 40
# fill description dictionary for easy step instantiation
description = dict()
description['problem_class'] = heat1d # pass problem class
description['sweeper_class'] = generic_LU # pass sweeper
description['sweeper_params'] = sweeper_params # pass sweeper parameters
description['level_params'] = level_params # pass level parameters
description['step_params'] = step_params # pass step parameters
description[
'space_transfer_class'] = mesh_to_mesh # pass spatial transfer class
description[
'space_transfer_params'] = space_transfer_params # pass paramters for spatial transfer
# set up parameters for PFASST run
problem_params['nvars'] = [63, 31]
description['problem_params'] = problem_params.copy()
description_pfasst = description.copy()
# set up parameters for MSSDC run
problem_params['nvars'] = [63]
description['problem_params'] = problem_params.copy()
description_mssdc = description.copy()
controller_params['mssdc_jac'] = True
controller_params_jac = controller_params.copy()
controller_params['mssdc_jac'] = False
controller_params_gs = controller_params.copy()
# set time parameters
t0 = 0.0
Tend = 1.0
# set up list of parallel time-steps to run PFASST/MSSDC with
num_proc = 8
# instantiate controllers
controller_mssdc_jac = controller_nonMPI(
num_procs=num_proc,
controller_params=controller_params_jac,
description=description_mssdc)
controller_mssdc_gs = controller_nonMPI(
num_procs=num_proc,
controller_params=controller_params_gs,
description=description_mssdc)
controller_pfasst = controller_nonMPI(num_procs=num_proc,
controller_params=controller_params,
description=description_pfasst)
# get initial values on finest level
P = controller_mssdc_jac.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main functions to get things done...
uend_pfasst, stats_pfasst = controller_pfasst.run(u0=uinit,
t0=t0,
Tend=Tend)
uend_mssdc_jac, stats_mssdc_jac = controller_mssdc_jac.run(u0=uinit,
t0=t0,
Tend=Tend)
uend_mssdc_gs, stats_mssdc_gs = controller_mssdc_gs.run(u0=uinit,
t0=t0,
Tend=Tend)
# compute exact solution and compare for both runs
uex = P.u_exact(Tend)
err_mssdc_jac = abs(uex - uend_mssdc_jac)
err_mssdc_gs = abs(uex - uend_mssdc_gs)
err_pfasst = abs(uex - uend_pfasst)
diff_jac = abs(uend_mssdc_jac - uend_pfasst)
diff_gs = abs(uend_mssdc_gs - uend_pfasst)
diff_jac_gs = abs(uend_mssdc_gs - uend_mssdc_jac)
f = open('step_8_B_out.txt', 'w')
out = 'Error PFASST: %12.8e' % err_pfasst
f.write(out + '\n')
print(out)
out = 'Error parallel MSSDC: %12.8e' % err_mssdc_jac
f.write(out + '\n')
print(out)
out = 'Error serial MSSDC: %12.8e' % err_mssdc_gs
f.write(out + '\n')
print(out)
out = 'Diff PFASST vs. parallel MSSDC: %12.8e' % diff_jac
f.write(out + '\n')
print(out)
out = 'Diff PFASST vs. serial MSSDC: %12.8e' % diff_gs
f.write(out + '\n')
print(out)
out = 'Diff parallel vs. serial MSSDC: %12.8e' % diff_jac_gs
f.write(out + '\n')
print(out)
# filter statistics by type (number of iterations)
filtered_stats_pfasst = filter_stats(stats_pfasst, type='niter')
filtered_stats_mssdc_jac = filter_stats(stats_mssdc_jac, type='niter')
filtered_stats_mssdc_gs = filter_stats(stats_mssdc_gs, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts_pfasst = sort_stats(filtered_stats_pfasst, sortby='time')
iter_counts_mssdc_jac = sort_stats(filtered_stats_mssdc_jac, sortby='time')
iter_counts_mssdc_gs = sort_stats(filtered_stats_mssdc_gs, sortby='time')
# compute and print statistics
for item_pfasst, item_mssdc_jac, item_mssdc_gs in \
zip(iter_counts_pfasst, iter_counts_mssdc_jac, iter_counts_mssdc_gs):
out = 'Number of iterations for time %4.2f (PFASST/parMSSDC/serMSSDC): %2i / %2i / %2i' % \
(item_pfasst[0], item_pfasst[1], item_mssdc_jac[1], item_mssdc_gs[1])
f.write(out + '\n')
print(out)
f.close()
# call helper routine to produce residual plot
show_residual_across_simulation(stats_mssdc_jac,
'step_8_residuals_mssdc_jac.png')
show_residual_across_simulation(stats_mssdc_gs,
'step_8_residuals_mssdc_gs.png')
assert os.path.isfile('step_8_residuals_mssdc_jac.png')
assert os.path.isfile('step_8_residuals_mssdc_gs.png')
assert diff_jac < 3.1E-10, \
"ERROR: difference between PFASST and parallel MSSDC controller is too large, got %s" % diff_jac
assert diff_gs < 3.1E-10, \
"ERROR: difference between PFASST and serial MSSDC controller is too large, got %s" % diff_gs
assert diff_jac_gs < 3.1E-10, \
"ERROR: difference between parallel and serial MSSDC controller is too large, got %s" % diff_jac_gs
def run_simulations(type=None,
ndim_list=None,
Tend=None,
nsteps_list=None,
ml=False,
nprocs=None):
"""
A simple test program to do SDC runs for the heat equation in various dimensions
"""
t0 = None
dt = None
description = None
controller_params = None
f = open('step_8_C_out.txt', 'a')
for ndim in ndim_list:
for nsteps in nsteps_list:
if type == 'diffusion':
# set time parameters
t0 = 0.0
dt = (Tend - t0) / nsteps
description, controller_params = setup_diffusion(dt, ndim, ml)
elif type == 'advection':
# set time parameters
t0 = 0.0
dt = (Tend - t0) / nsteps
description, controller_params = setup_advection(dt, ndim, ml)
elif type == 'auzinger':
assert ndim == 1
# set time parameters
t0 = 0.0
dt = (Tend - t0) / nsteps
description, controller_params = setup_auzinger(dt, ml)
out = f'Running {type} in {ndim} dimensions with time-step size {dt}...\n'
f.write(out + '\n')
print(out)
# Warning: this is black magic used to run an 'exact' collocation solver for each step within the hooks
description['step_params']['description'] = description
description['step_params']['controller_params'] = controller_params
# instantiate controller
controller = controller_nonMPI(num_procs=nprocs,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# filter statistics by type (number of iterations)
iter_counts = sort_stats(filter_stats(stats, type='niter'),
sortby='time')
niters = np.array([item[1] for item in iter_counts])
out = f' Mean number of iterations: {np.mean(niters):4.2f}'
f.write(out + '\n')
print(out)
# filter statistics by type (error after time-step)
PDE_errors = sort_stats(filter_stats(stats,
type='PDE_error_after_step'),
sortby='time')
coll_errors = sort_stats(filter_stats(
stats, type='coll_error_after_step'),
sortby='time')
for iters, PDE_err, coll_err in zip(iter_counts, PDE_errors,
coll_errors):
assert coll_err[1] < description['step_params'][
'errtol'], f'Error too high, got {coll_err[1]:8.4e}'
out = f' Errors after step {PDE_err[0]:8.4f} with {iters[1]} iterations: ' \
f'{PDE_err[1]:8.4e} / {coll_err[1]:8.4e}'
f.write(out + '\n')
print(out)
f.write('\n')
print()
# filter statistics by type (error after time-step)
timing = sort_stats(filter_stats(stats, type='timing_run'),
sortby='time')
out = f'...done, took {timing[0][1]} seconds!'
f.write(out + '\n')
print(out)
print()
out = '-----------------------------------------------------------------------------'
f.write(out + '\n')
print(out)
f.close()
def main():
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-10
level_params['dt'] = 0.01
# This comes as read-in for the step class (this is optional!)
step_params = dict()
step_params['maxiter'] = 50
# This comes as read-in for the problem class
problem_params = dict()
problem_params['nu'] = 1
problem_params['nvars'] = 255
problem_params['lambda0'] = 5.0
problem_params['newton_maxiter'] = 50
problem_params['newton_tol'] = 1E-12
problem_params['interval'] = (-5, 5)
# This comes as read-in for the sweeper class
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = 5
sweeper_params['QI'] = 'LU'
sweeper_params['fixed_time_in_jacobian'] = 0
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = generalized_fisher_jac
description['problem_params'] = problem_params
description['sweeper_params'] = sweeper_params
description['level_params'] = level_params
description['step_params'] = step_params
sweeper_list = [
generic_implicit, linearized_implicit_fixed_parallel_prec,
linearized_implicit_fixed_parallel, linearized_implicit_parallel
]
f = open('parallelSDC_nonlinear_out.txt', 'w')
uinit = None
uex = None
uend = None
P = None
# loop over the different sweepers and check results
for sweeper in sweeper_list:
description['sweeper_class'] = sweeper
# instantiate the controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# setup parameters "in time"
t0 = 0
Tend = 0.1
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# compute exact solution and compare
uex = P.u_exact(Tend)
err = abs(uex - uend)
print('error at time %s: %s' % (Tend, err))
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
f.write(out + '\n')
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(
niters)
f.write(out + '\n')
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
f.write(out + '\n')
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % \
(float(np.std(niters)), float(np.var(niters)))
f.write(out + '\n')
f.write(out + '\n')
print(out)
f.write('\n')
print()
assert err < 3.686e-05, 'ERROR: error is too high for sweeper %s, got %s' % (
sweeper.__name__, err)
assert np.mean(niters) == 7.5 or np.mean(niters) == 4.0, \
'ERROR: mean number of iterations not as expected, got %s' % np.mean(niters)
f.close()
results = dict()
results['interval'] = problem_params['interval']
results['xvalues'] = np.array([(i + 1 - (P.params.nvars + 1) / 2) * P.dx
for i in range(P.params.nvars)])
results['uinit'] = uinit.values
results['uend'] = uend.values
results['uex'] = uex.values
# write out for later visualization
file = open('data/parallelSDC_results_graphs.pkl', 'wb')
pickle.dump(results, file)
assert os.path.isfile('data/parallelSDC_results_graphs.pkl'
), 'ERROR: pickle did not create file'
def run_simulation():
"""
Routine to run the simulation of a second order problem
"""
# initialize level parameters
level_params = dict()
level_params['restol'] = 0.0
level_params['dt'] = 1.0
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussLobatto
sweeper_params['num_nodes'] = [5, 3]
sweeper_params['initial_guess'] = 'zero'
# initialize problem parameters for the Penning trap
problem_params = dict()
problem_params['k'] = None # will be defined later
problem_params['phase'] = 0.0
problem_params['amp'] = 1.0
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 50
# initialize controller parameters
controller_params = dict()
controller_params['hook_class'] = stop_at_error_hook
controller_params['logger_level'] = 30
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = harmonic_oscillator
description['sweeper_class'] = verlet
description['level_params'] = level_params
description['step_params'] = step_params
description['space_transfer_class'] = particles_to_particles
# set time parameters
t0 = 0.0
Tend = 4.0
num_procs = 4
rlim_left = 0
rlim_right = 16.0
nstep = 34
ks = np.linspace(rlim_left, rlim_right, nstep)[1:]
# qd_combinations = [('IE', 'EE'), ('IE', 'PIC'),
# ('LU', 'EE'), ('LU', 'PIC'),
# # ('MIN3', 'PIC'), ('MIN3', 'EE'),
# ('PIC', 'EE'), ('PIC', 'PIC')]
qd_combinations = [('IE', 'EE'), ('PIC', 'PIC')]
results = dict()
results['ks'] = ks
for qd in qd_combinations:
print('Working on combination (%s, %s)...' % qd)
niters = np.zeros(len(ks))
for i, k in enumerate(ks):
problem_params['k'] = k
description['problem_params'] = problem_params
sweeper_params['QI'] = qd[0]
sweeper_params['QE'] = qd[1]
description['sweeper_params'] = sweeper_params
# instantiate the controller
controller = controller_nonMPI(num_procs=num_procs,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t=t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
uex = P.u_exact(Tend)
print('Error after run: %s' % abs(uex - uend))
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
niters[i] = np.mean(np.array([item[1] for item in iter_counts]))
# print('Worked on k = %s, took %s iterations' % (k, results[i]))
results[qd] = niters
fname = 'data/harmonic_k.dat'
f = open(fname, 'wb')
dill.dump(results, f)
f.close()
assert os.path.isfile(fname), 'Run for %s did not create stats file' % prob
def run_variants(variant=None, ml=None, num_procs=None):
"""
Main routine to run the different implementations of the heat equation with FEniCS
Args:
variant (str): specifies the variant
ml (bool): use single or multiple levels
num_procs (int): number of processors in time
"""
Tend = 1.0
t0 = 0.0
description, controller_params = setup(t0=t0, ml=ml)
if variant == 'mass':
# Note that we need to reduce the tolerance for the residual here, since otherwise the error will be too high
description['level_params']['restol'] /= 500
description['problem_class'] = fenics_heat_mass
description['sweeper_class'] = imex_1st_order_mass
elif variant == 'mass_inv':
description['problem_class'] = fenics_heat
description['sweeper_class'] = imex_1st_order
elif variant == 'weak':
description['problem_class'] = fenics_heat_weak_imex
description['sweeper_class'] = imex_1st_order
else:
raise NotImplementedError('Variant %s is not implemented' % variant)
# quickly generate block of steps
controller = controller_nonMPI(num_procs=num_procs,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(0.0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# compute exact solution and compare
uex = P.u_exact(Tend)
err = abs(uex - uend) / abs(uex)
f = open('step_7_A_out.txt', 'a')
out = f'Variant {variant} with ml={ml} and num_procs={num_procs} -- error at time {Tend}: {err}'
f.write(out + '\n')
print(out)
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
f.write(out + '\n')
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(niters)
f.write(out + '\n')
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
f.write(out + '\n')
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (float(
np.std(niters)), float(np.var(niters)))
f.write(out + '\n')
print(out)
timing = sort_stats(filter_stats(stats, type='timing_run'), sortby='time')
out = f'Time to solution: {timing[0][1]:6.4f} sec.'
f.write(out + '\n')
print(out)
if num_procs == 1:
assert np.mean(
niters
) <= 6.0, 'Mean number of iterations is too high, got %s' % np.mean(
niters)
assert err <= 4.1E-08, 'Error is too high, got %s' % err
else:
assert np.mean(
niters
) <= 11.6, 'Mean number of iterations is too high, got %s' % np.mean(
niters)
assert err <= 4.0E-08, 'Error is too high, got %s' % err
f.write('\n')
print()
f.close()
def main(comm=None):
# initialize level parameters (part I)
level_params = dict()
level_params['restol'] = 1E-08
# initialize sweeper parameters (part I)
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = comm.Get_size()
sweeper_params['comm'] = comm
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 100
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30
# set up list of Q-delta types and setups
qd_list = ['IEpar', 'Qpar', 'MIN', 'MIN3']
setup_list = [('heat', 63, [10.0**i for i in range(-3, 3)]),
('advection', 64, [10.0**i for i in range(-3, 3)]),
('vanderpol', 2, [0.1 * 2**i for i in range(0, 10)]),
('fisher', 63, [2**i for i in range(-2, 3)])]
# setup_list = [('fisher', 63, [2 * i for i in range(1, 6)])]
# pre-fill results with lists of setups
results = dict()
for setup, nvars, param_list in setup_list:
results[setup] = (nvars, param_list)
# loop over all Q-delta matrix types
for qd_type in qd_list:
# assign implicit Q-delta matrix
sweeper_params['QI'] = qd_type
# loop over all setups
for setup, nvars, param_list in setup_list:
# initialize problem parameters (part I)
problem_params = dict()
problem_params[
'nvars'] = nvars # number of degrees of freedom for each level
# loop over all parameters
for param in param_list:
# fill description for the controller
description = dict()
description[
'sweeper_class'] = generic_implicit_MPI # pass sweeper
description[
'sweeper_params'] = sweeper_params # pass sweeper parameters
description[
'step_params'] = step_params # pass step parameters
# description['base_transfer_class'] = base_transfer_mpi
print('working on: %s - %s - %s' % (qd_type, setup, param))
# decide which setup to take
if setup == 'heat':
problem_params['nu'] = param
problem_params['freq'] = 2
level_params['dt'] = 0.1
description['problem_class'] = heat1d
description['problem_params'] = problem_params
description[
'level_params'] = level_params # pass level parameters
elif setup == 'advection':
problem_params['c'] = param
problem_params['order'] = 2
problem_params['freq'] = 2
level_params['dt'] = 0.1
description['problem_class'] = advection1d
description['problem_params'] = problem_params
description[
'level_params'] = level_params # pass level parameters
elif setup == 'vanderpol':
problem_params['newton_tol'] = 1E-09
problem_params['newton_maxiter'] = 20
problem_params['mu'] = param
problem_params['u0'] = np.array([2.0, 0])
level_params['dt'] = 0.1
description['problem_class'] = vanderpol
description['problem_params'] = problem_params
description['level_params'] = level_params
elif setup == 'fisher':
problem_params['nu'] = 1
problem_params['lambda0'] = param
problem_params['newton_maxiter'] = 20
problem_params['newton_tol'] = 1E-10
problem_params['interval'] = (-5, 5)
level_params['dt'] = 0.01
description['problem_class'] = generalized_fisher
description['problem_params'] = problem_params
description['level_params'] = level_params
else:
print('Setup not implemented..', setup)
exit()
# instantiate controller
controller = controller_nonMPI(
num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit,
t0=0,
Tend=level_params['dt'])
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# just one time-step, grep number of iteration and store
niter = iter_counts[0][1]
id = ID(setup=setup, qd_type=qd_type, param=param)
results[id] = niter
assert len(results) == (
6 + 6 + 10 +
5) * 4 + 4, 'ERROR: did not get all results, got %s' % len(results)
if comm.Get_rank() == 0:
# write out for later visualization
file = open('data/parallelSDC_iterations_precond_MPI.pkl', 'wb')
pickle.dump(results, file)
assert os.path.isfile('data/parallelSDC_iterations_precond_MPI.pkl'
), 'ERROR: pickle did not create file'
def run(sweeper_list, MPI_fake=True, controller_comm=MPI.COMM_WORLD, node_comm=None, node_list=None):
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-10
# This comes as read-in for the step class (this is optional!)
step_params = dict()
step_params['maxiter'] = 50
# This comes as read-in for the problem class
problem_params = dict()
problem_params['nu'] = 2
problem_params['nvars'] = [(256,256), (128, 128)]
problem_params['eps'] = [0.04]
problem_params['newton_maxiter'] = 1 #50
problem_params['newton_tol'] = 1E-11
problem_params['lin_tol'] = 1E-12
problem_params['lin_maxiter'] = 450 #0
problem_params['radius'] = 0.25
problem_params['comm'] = node_comm #time_comm #MPI.COMM_WORLD #node_comm
# This comes as read-in for the sweeper class
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = 4
sweeper_params['QI'] = 'LU'
sweeper_params['fixed_time_in_jacobian'] = 0
sweeper_params['comm'] = node_comm
sweeper_params['node_list'] = node_list
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30
controller_params['hook_class'] = err_reduction_hook
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = AC_jac
description['problem_params'] = problem_params
description['sweeper_params'] = sweeper_params
description['step_params'] = step_params
description['space_transfer_class'] = mesh_to_mesh
#description['space_transfer_class'] = base_transfer_MPI #mesh_to_mesh
#assert MPI.COMM_WORLD.Get_size() == sweeper_params['num_nodes']
# setup parameters "in time"
t0 = 0
Tend = 0.024
# loop over the different sweepers and check results
serial =True
for sweeper in sweeper_list:
description['sweeper_class'] = sweeper
error_reduction = []
for dt in [1e-3]:
print('Working with sweeper %s and dt = %s...' % (sweeper.__name__, dt))
level_params['dt'] = dt
description['level_params'] = level_params
# instantiate the controller and stuff
if(sweeper.__name__=='generic_implicit'):
if(controller_comm.Get_size()==1):
controller = controller_nonMPI(num_procs=1, controller_params=controller_params, description=description)
serial=False
else:
controller = controller_MPI(controller_params=controller_params, description=description, comm=controller_comm)
elif (sweeper.__name__=='linearized_implicit_fixed_parallel_prec_MPI'or sweeper.__name__=="linearized_implicit_fixed_parallel_MPI" or sweeper.__name__=='linearized_implicit_fixed_parallel_prec'or sweeper.__name__=="linearized_implicit_fixed_parallel"):
#if(node_comm is None):
#description['base_transfer_class'] = base_transfer
#controller = controller_MPI(controller_params=controller_params, description=description, comm=controller_comm)
#else:
# serial==False
if (sweeper.__name__=='linearized_implicit_fixed_parallel_prec_MPI'or sweeper.__name__=="linearized_implicit_fixed_parallel_MPI"):
description['base_transfer_class'] = base_transfer_MPI
controller = controller_MPI(controller_params=controller_params, description=description, comm=controller_comm)
else:
controller = controller_MPI(controller_params=controller_params, description=description, comm=controller_comm)
#controller = controller_nonMPI(num_procs=1, controller_params=controller_params, description=description)
#serial=False
elif (sweeper.__name__=='div_linearized_implicit_fixed_parallel_prec_MPI' or sweeper.__name__=='div_linearized_implicit_fixed_parallel_MPI'):
description['base_transfer_class'] = div_base_transfer_MPI
controller = controller_MPI(controller_params=controller_params, description=description, comm=controller_comm)
serial==False
if(serial==True):
P = controller.S.levels[0].prob
else:
P = controller.MS[0].levels[0].prob
# get initial values on finest level
uinit = P.u_exact(t0)
# call main function to get things done...
MPI.COMM_WORLD.Barrier()
t1 = MPI.Wtime()
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
t2 = MPI.Wtime()
time =t2-t1
print( "My elapsed time is ", time)
maxtime=time
maxtime = np.zeros(1, dtype='float64')
local_time = np.max(time).astype('float64')
MPI.COMM_WORLD.Allreduce(local_time,maxtime, op=MPI.MAX)
print( "Elapsed max time is ", maxtime[0])
if(True): #control the solution
fname = 'ref_24.npz'
loaded = np.load(fname)
uref = loaded['uend']
print("Fehler ", np.linalg.norm(uref-uend.values, np.inf))
print("Abweichung vom Anfangswert ", np.linalg.norm(uinit.values-uend.values, np.inf))
# compute and print statistics
filtered_stats = filter_stats(stats, type='niter')
iter_counts = sort_stats(filtered_stats, sortby='time')
niters = np.array([item[1] for item in iter_counts])
print("Iterationen SDC ", niters)
print("Newton Iterationen ", P.newton_itercount)
maxcount = np.zeros(1, dtype='float64')
local_count = np.max(P.newton_itercount).astype('float64')
MPI.COMM_WORLD.Allreduce(local_count,maxcount, op=MPI.MAX)
print("maxiter ", maxcount[0])
if(serial==False):
for pp in controller.MS:
print("Newton Iter ", pp.levels[0].prob.newton_itercount)
#print("lineare Iter ", pp.levels[0].prob.linear_count)
#print("warning ", pp.levels[0].prob.warning_count)
#print("time for linear solve ", pp.levels[0].prob.time_for_solve)
else:
print("Newton Iter ", controller.S.levels[0].prob.newton_itercount)
#print("lineare Iter ", controller.S.levels[0].prob.linear_count)
#print("warning ", controller.S.levels[0].prob.warning_count)
#print("time for linear solve ", controller.S.levels[0].prob.time_for_solve)
MPI.COMM_WORLD.Barrier()
print("------------------------------------------------------------------------------------------------------------------------------------------")
def compute_and_plot_itererror():
"""
Routine to compute and plot the error over the iterations for difference cs values
"""
num_procs = 1
t0 = 0.0
Tend = 0.025
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-10
level_params['dt'] = Tend
# This comes as read-in for the step class
step_params = dict()
step_params['maxiter'] = 15
# This comes as read-in for the problem class
problem_params = dict()
problem_params['cadv'] = 0.1
problem_params['nvars'] = [(2, 300)]
problem_params['order_adv'] = 5
problem_params['waveno'] = 5
# This comes as read-in for the sweeper class
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['do_coll_update'] = True
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30
controller_params['hook_class'] = dump_energy
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = acoustic_1d_imex
description['sweeper_class'] = imex_1st_order
description['step_params'] = step_params
description['level_params'] = level_params
cs_v = [0.5, 1.0, 1.5, 5.0]
nodes_v = [3]
residual = np.zeros(
(np.size(cs_v), np.size(nodes_v), step_params['maxiter']))
convrate = np.zeros(
(np.size(cs_v), np.size(nodes_v), step_params['maxiter'] - 1))
lastiter = np.zeros(
(np.size(cs_v), np.size(nodes_v))) + step_params['maxiter']
avg_convrate = np.zeros((np.size(cs_v), np.size(nodes_v)))
P = None
for cs_ind in range(0, np.size(cs_v)):
problem_params['cs'] = cs_v[cs_ind]
description['problem_params'] = problem_params
for nodes_ind in np.arange(np.size(nodes_v)):
sweeper_params['num_nodes'] = nodes_v[nodes_ind]
description['sweeper_params'] = sweeper_params
# instantiate the controller
controller = controller_nonMPI(num_procs=num_procs,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
print("Fast CFL number: %4.2f" %
(problem_params['cs'] * level_params['dt'] / P.dx))
print("Slow CFL number: %4.2f" %
(problem_params['cadv'] * level_params['dt'] / P.dx))
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
extract_stats = filter_stats(stats, type='residual_post_iteration')
for k, v in extract_stats.items():
iter = getattr(k, 'iter')
if iter is not -1:
residual[cs_ind, nodes_ind, iter - 2] = v
# Compute convergence rates
for iter in range(0, step_params['maxiter'] - 1):
if residual[cs_ind, nodes_ind, iter] < level_params['restol']:
lastiter[cs_ind, nodes_ind] = iter
else:
convrate[cs_ind, nodes_ind, iter] = residual[cs_ind, nodes_ind, iter + 1] / \
residual[cs_ind, nodes_ind, iter]
print(lastiter[cs_ind, nodes_ind])
avg_convrate[cs_ind, nodes_ind] = np.sum(convrate[cs_ind, nodes_ind, :]) / \
float(lastiter[cs_ind, nodes_ind])
# Plot the results
fs = 8
color = ['r', 'b', 'g', 'c']
shape = ['o', 'd', 's', 'v']
rcParams['figure.figsize'] = 2.5, 2.5
rcParams['pgf.rcfonts'] = False
fig = plt.figure()
for ii in range(0, np.size(cs_v)):
x = np.arange(1, lastiter[ii, 0] - 1)
y = convrate[ii, 0, 0:int(lastiter[ii, 0]) - 2]
plt.plot(x,
y,
linestyle='-',
marker=shape[ii],
markersize=fs - 2,
color=color[ii],
label=r'$C_{fast}$=%4.2f' %
(cs_v[ii] * level_params['dt'] / P.dx))
plt.legend(loc='upper right', fontsize=fs, prop={'size': fs - 2})
plt.xlabel('Iteration', fontsize=fs)
plt.ylabel(r'$|| r^{k+1} ||_{\infty}/|| r^k ||_{\infty}$',
fontsize=fs,
labelpad=2)
plt.xlim([0, step_params['maxiter']])
plt.ylim([0, 1.0])
plt.yticks(fontsize=fs)
plt.xticks(fontsize=fs)
filename = 'data/iteration.png'
fig.savefig(filename, bbox_inches='tight')
def main():
"""
A simple test program to do PFASST runs for the heat equation
"""
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-14
level_params['dt'] = 0.9 / 32
level_params['nsweeps'] = 1
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussLobatto
sweeper_params['num_nodes'] = [5, 3, 2]
sweeper_params['QI'] = [
'LU'
] # For the IMEX sweeper, the LU-trick can be activated for the implicit part
sweeper_params['initial_guess'] = 'spread'
sweeper_params['do_coll_update'] = False
# initialize problem parameters
problem_params = dict()
problem_params['nu'] = 0.02 # diffusion coefficient
problem_params['c'] = 1.0 # advection speed
problem_params['freq'] = -1 # frequency for the test value
problem_params['nvars'] = [256, 128, 64
] # number of degrees of freedom for each level
problem_params['L'] = 1.0 # length of the interval [-L/2, L/2]
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 10
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30
controller_params['hook_class'] = libpfasst_output
# fill description dictionary for easy step instantiation
description = dict()
# description['problem_class'] = advectiondiffusion1d_imex # pass problem class
description[
'problem_class'] = advectiondiffusion1d_implicit # pass problem class
description['problem_params'] = problem_params # pass problem parameters
# description['sweeper_class'] = imex_1st_order # pass sweeper
description['sweeper_class'] = generic_implicit # pass sweeper
description['sweeper_params'] = sweeper_params # pass sweeper parameters
description['level_params'] = level_params # pass level parameters
description['step_params'] = step_params # pass step parameters
description[
'space_transfer_class'] = mesh_to_mesh_fft # pass spatial transfer class
description['space_transfer_params'] = dict(
) # pass paramters for spatial transfer
# set time parameters
t0 = 0.0
Tend = level_params['dt']
num_proc = 1
# instantiate controller
controller = controller_nonMPI(num_procs=num_proc,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# print(controller.MS[0].levels[0].sweep.coll.Qmat)
# print(controller.MS[0].levels[0].sweep.QI)
# exit()
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# compute exact solution and compare
uex = P.u_exact(Tend)
err = abs(uex - uend)
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
for item in iter_counts:
out = 'Number of iterations for time %4.2f: %2i' % item
print(out)
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(niters)
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (float(
np.std(niters)), float(np.var(niters)))
print(out)
print('Error: %8.4e' % err)
def run_variant(nlevels=None):
"""
Routine to run particular SDC variant
Args:
Returns:
"""
# load (incomplete) default parameters
description, controller_params = setup_parameters()
# add stuff based on variant
if nlevels == 1:
description['level_params']['nsweeps'] = 1
description['problem_params']['nvars'] = [(128, 128)]
# description['problem_params']['nvars'] = [(32, 32)]
elif nlevels == 2:
description['level_params']['nsweeps'] = [1, 1]
description['problem_params']['nvars'] = [(128, 128), (32, 32)]
# description['problem_params']['nvars'] = [(32, 32), (16, 16)]
else:
raise NotImplemented('Wrong variant specified, got %s' % nlevels)
out = 'Working on %s levels...' % nlevels
print(out)
# setup parameters "in time"
t0 = 0.0
Tend = 0.032
# instantiate controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# filter statistics by variant (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(niters)
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (float(
np.std(niters)), float(np.var(niters)))
print(out)
timing = sort_stats(filter_stats(stats, type='timing_run'), sortby='time')
print('Time to solution: %6.4f sec.' % timing[0][1])
fname = 'data/AC_reference_FFT_Tend{:.1e}'.format(Tend) + '.npz'
loaded = np.load(fname)
uref = loaded['uend']
err = np.linalg.norm(uref - uend.values, np.inf)
print('Error vs. reference solution: %6.4e' % err)
print()
return stats
def compute_and_plot_solutions():
"""
Routine to compute and plot the solutions of SDC(2), IMEX, BDF-2 and RK for a multiscale problem
"""
num_procs = 1
t0 = 0.0
Tend = 3.0
nsteps = 154 # 154 is value in Vater et al.
dt = Tend / float(nsteps)
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-10
level_params['dt'] = dt
# This comes as read-in for the step class
step_params = dict()
step_params['maxiter'] = 2
# This comes as read-in for the problem class
problem_params = dict()
problem_params['cadv'] = 0.05
problem_params['cs'] = 1.0
problem_params['nvars'] = [(2, 512)]
problem_params['order_adv'] = 5
problem_params['waveno'] = 5
# This comes as read-in for the sweeper class
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = 2
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30
controller_params['hook_class'] = dump_energy
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = acoustic_1d_imex_multiscale
description['problem_params'] = problem_params
description['sweeper_class'] = imex_1st_order
description['sweeper_params'] = sweeper_params
description['step_params'] = step_params
description['level_params'] = level_params
# instantiate the controller
controller = controller_nonMPI(num_procs=num_procs,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# instantiate standard integrators to be run for comparison
trap = trapezoidal((P.A + P.Dx).astype('complex'), 0.5)
bdf2_m = bdf2(P.A + P.Dx)
dirk_m = dirk((P.A + P.Dx).astype('complex'), step_params['maxiter'])
rkimex = rk_imex(P.A.astype('complex'), P.Dx.astype('complex'),
step_params['maxiter'])
y0_tp = np.concatenate((uinit.values[0, :], uinit.values[1, :]))
y0_bdf = y0_tp
y0_dirk = y0_tp.astype('complex')
y0_imex = y0_tp.astype('complex')
# Perform time steps with standard integrators
for i in range(0, nsteps):
# trapezoidal rule step
ynew_tp = trap.timestep(y0_tp, dt)
# BDF-2 scheme
if i == 0:
ynew_bdf = bdf2_m.firsttimestep(y0_bdf, dt)
ym1_bdf = y0_bdf
else:
ynew_bdf = bdf2_m.timestep(y0_bdf, ym1_bdf, dt)
# DIRK scheme
ynew_dirk = dirk_m.timestep(y0_dirk, dt)
# IMEX scheme
ynew_imex = rkimex.timestep(y0_imex, dt)
y0_tp = ynew_tp
ym1_bdf = y0_bdf
y0_bdf = ynew_bdf
y0_dirk = ynew_dirk
y0_imex = ynew_imex
# Finished running standard integrators
unew_tp, pnew_tp = np.split(ynew_tp, 2)
unew_bdf, pnew_bdf = np.split(ynew_bdf, 2)
unew_dirk, pnew_dirk = np.split(ynew_dirk, 2)
unew_imex, pnew_imex = np.split(ynew_imex, 2)
fs = 8
rcParams['figure.figsize'] = 2.5, 2.5
# rcParams['pgf.rcfonts'] = False
fig = plt.figure()
sigma_0 = 0.1
k = 7.0 * 2.0 * np.pi
x_0 = 0.75
x_1 = 0.25
print('Maximum pressure in SDC: %5.3e' %
np.linalg.norm(uend.values[1, :], np.inf))
print('Maximum pressure in DIRK: %5.3e' %
np.linalg.norm(pnew_dirk, np.inf))
print('Maximum pressure in RK-IMEX: %5.3e' %
np.linalg.norm(pnew_imex, np.inf))
if dirk_m.order == 2:
plt.plot(P.mesh,
pnew_bdf,
'd-',
color='c',
label='BDF-2',
markevery=(50, 75))
p_slow = np.exp(
-np.square(np.mod(P.mesh - problem_params['cadv'] * Tend, 1.0) - x_0) /
(sigma_0 * sigma_0))
plt.plot(P.mesh,
p_slow,
'--',
color='k',
markersize=fs - 2,
label='Slow mode',
dashes=(10, 2))
if np.linalg.norm(pnew_imex, np.inf) <= 2:
plt.plot(P.mesh,
pnew_imex,
'+-',
color='r',
label='IMEX(' + str(rkimex.order) + ')',
markevery=(1, 75),
mew=1.0)
plt.plot(P.mesh,
uend.values[1, :],
'o-',
color='b',
label='SDC(' + str(step_params['maxiter']) + ')',
markevery=(25, 75))
plt.plot(P.mesh,
pnew_dirk,
'-',
color='g',
label='DIRK(' + str(dirk_m.order) + ')')
plt.xlabel('x', fontsize=fs, labelpad=0)
plt.ylabel('Pressure', fontsize=fs, labelpad=0)
fig.gca().set_xlim([0, 1.0])
fig.gca().set_ylim([-0.5, 1.1])
fig.gca().tick_params(axis='both', labelsize=fs)
plt.legend(loc='upper left',
fontsize=fs,
prop={'size': fs},
handlelength=3)
fig.gca().grid()
filename = 'data/multiscale-K' + str(step_params['maxiter']) + '-M' + str(
sweeper_params['num_nodes']) + '.png'
plt.gcf().savefig(filename, bbox_inches='tight')
def run_variant(variant=None):
"""
Routine to run a particular variant
Args:
variant (str): string describing the variant
"""
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-07
level_params['dt'] = 1E-03 / 2
level_params['nsweeps'] = 1
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = 3
sweeper_params['initial_guess'] = 'zero'
# This comes as read-in for the problem class
problem_params = dict()
problem_params['nu'] = 2
problem_params['eps'] = 0.04
problem_params['newton_maxiter'] = 100
problem_params['newton_tol'] = 1E-08
problem_params['lin_tol'] = 1E-09
problem_params['lin_maxiter'] = 100
problem_params['radius'] = 0.25
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 50
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30
controller_params['hook_class'] = monitor
# fill description dictionary for easy step instantiation
description = dict()
description['problem_class'] = allencahn_fullyimplicit
description['level_params'] = level_params # pass level parameters
description['step_params'] = step_params # pass step parameters
do_print = True
# add stuff based on variant
if variant == 'sl_serial':
maxmeaniters = 5.0
sweeper_params['QI'] = ['LU']
problem_params['nvars'] = [(128, 128)]
description[
'problem_params'] = problem_params # pass problem parameters
description['sweeper_class'] = generic_implicit # pass sweeper
description[
'sweeper_params'] = sweeper_params # pass sweeper parameters
elif variant == 'sl_parallel':
maxmeaniters = 5.12
assert MPI.COMM_WORLD.Get_size() == sweeper_params['num_nodes']
sweeper_params['QI'] = ['MIN3']
sweeper_params['comm'] = MPI.COMM_WORLD
problem_params['nvars'] = [(128, 128)]
description[
'problem_params'] = problem_params # pass problem parameters
description['sweeper_class'] = generic_implicit_MPI # pass sweeper
description[
'sweeper_params'] = sweeper_params # pass sweeper parameters
do_print = MPI.COMM_WORLD.Get_rank() == 0
elif variant == 'ml_serial':
maxmeaniters = 3.125
sweeper_params['QI'] = ['LU']
problem_params['nvars'] = [(128, 128), (64, 64)]
description['space_transfer_class'] = mesh_to_mesh_fft2d
description[
'problem_params'] = problem_params # pass problem parameters
description['sweeper_class'] = generic_implicit # pass sweeper
description[
'sweeper_params'] = sweeper_params # pass sweeper parameters
elif variant == 'ml_parallel':
assert MPI.COMM_WORLD.Get_size() == sweeper_params['num_nodes']
maxmeaniters = 4.25
sweeper_params['QI'] = ['MIN3']
sweeper_params['comm'] = MPI.COMM_WORLD
problem_params['nvars'] = [(128, 128), (64, 64)]
description[
'problem_params'] = problem_params # pass problem parameters
description['sweeper_class'] = generic_implicit_MPI # pass sweeper
description[
'sweeper_params'] = sweeper_params # pass sweeper parameters
description['space_transfer_class'] = mesh_to_mesh_fft2d
description['base_transfer_class'] = base_transfer_MPI
do_print = MPI.COMM_WORLD.Get_rank() == 0
else:
raise NotImplemented('Wrong variant specified, got %s' % variant)
if do_print:
out = 'Working on %s variant...' % variant
print(out)
# setup parameters "in time"
t0 = 0
Tend = 0.004
# instantiate controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# filter statistics by variant (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
niters = np.array([item[1] for item in iter_counts])
if do_print:
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
assert np.mean(niters) <= maxmeaniters, 'ERROR: number of iterations is too high, got %s instead of %s' \
% (np.mean(niters), maxmeaniters)
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(
niters)
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (
float(np.std(niters)), float(np.var(niters)))
print(out)
print(' Iteration count (nonlinear/linear): %i / %i' %
(P.newton_itercount, P.lin_itercount))
print(' Mean Iteration count per call: %4.2f / %4.2f' %
(P.newton_itercount / max(P.newton_ncalls, 1),
P.lin_itercount / max(P.lin_ncalls, 1)))
timing = sort_stats(filter_stats(stats, type='timing_run'),
sortby='time')
print('Time to solution: %6.4f sec.' % timing[0][1])
return None
def run_simulation(spectral=None, ml=None, num_procs=None):
"""
A test program to do SDC, MLSDC and PFASST runs for the 2D NLS equation
Args:
spectral (bool): run in real or spectral space
ml (bool): single or multiple levels
num_procs (int): number of parallel processors
"""
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-08
level_params['dt'] = 1E-01 / 2
level_params['nsweeps'] = [1]
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = [3]
sweeper_params['QI'] = [
'LU'
] # For the IMEX sweeper, the LU-trick can be activated for the implicit part
sweeper_params['initial_guess'] = 'zero'
# initialize problem parameters
problem_params = dict()
if ml:
problem_params['nvars'] = [(128, 128), (32, 32)]
else:
problem_params['nvars'] = [(128, 128)]
problem_params['spectral'] = spectral
problem_params['comm'] = comm
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 50
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30 if rank == 0 else 99
# controller_params['predict_type'] = 'fine_only'
# fill description dictionary for easy step instantiation
description = dict()
description['problem_params'] = problem_params # pass problem parameters
description['problem_class'] = nonlinearschroedinger_imex
description['sweeper_class'] = imex_1st_order
description['sweeper_params'] = sweeper_params # pass sweeper parameters
description['level_params'] = level_params # pass level parameters
description['step_params'] = step_params # pass step parameters
description['space_transfer_class'] = fft_to_fft
# set time parameters
t0 = 0.0
Tend = 1.0
f = None
if rank == 0:
f = open('step_7_B_out.txt', 'a')
out = f'Running with ml={ml} and num_procs={num_procs}...'
f.write(out + '\n')
print(out)
# instantiate controller
controller = controller_nonMPI(num_procs=num_procs,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
uex = P.u_exact(Tend)
err = abs(uex - uend)
if rank == 0:
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
niters = np.array([item[1] for item in iter_counts])
out = f' Min/Mean/Max number of iterations: ' \
f'{np.min(niters):4.2f} / {np.mean(niters):4.2f} / {np.max(niters):4.2f}'
f.write(out + '\n')
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(
niters)
f.write(out + '\n')
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
f.write(out + '\n')
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (
float(np.std(niters)), float(np.var(niters)))
f.write(out + '\n')
print(out)
out = f'Error: {err:6.4e}'
f.write(out + '\n')
print(out)
timing = sort_stats(filter_stats(stats, type='timing_run'),
sortby='time')
out = f'Time to solution: {timing[0][1]:6.4f} sec.'
f.write(out + '\n')
print(out)
assert err <= 1.133E-05, 'Error is too high, got %s' % err
if ml:
if num_procs > 1:
maxmean = 12.5
else:
maxmean = 6.6
else:
maxmean = 12.7
assert np.mean(
niters
) <= maxmean, 'Mean number of iterations is too high, got %s' % np.mean(
niters)
f.write('\n')
print()
f.close()
# Fill description dictionary for easy hierarchy creation
description = dict()
description['problem_class'] = fenics_heat_mass
description['problem_params'] = problem_params
description['sweeper_class'] = imex_1st_order_mass
description['sweeper_params'] = sweeper_params
description['level_params'] = level_params
description['step_params'] = step_params
description['space_transfer_class'] = mesh_to_mesh_fenics
description['base_transfer_class'] = base_transfer_mass
description['base_transfer_params'] = base_transfer_params
# quickly generate block of steps
controller = controller_nonMPI(num_procs=num_procs,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# compute exact solution and compare
uex = P.u_exact(Tend)
print('(classical) error at time %s: %s' %
(Tend, abs(uex - uend) / abs(uex)))
def run_diffusion(nsweeps):
"""
A simple test program to test PFASST convergence for the heat equation with random initial data
Args:
nsweeps: number of fine sweeps to perform
"""
# initialize level parameters
level_params = dict()
level_params['restol'] = 1E-08
level_params['dt'] = 0.25
level_params['nsweeps'] = [nsweeps, 1]
# initialize sweeper parameters
sweeper_params = dict()
sweeper_params['collocation_class'] = CollGaussRadau_Right
sweeper_params['num_nodes'] = [3]
sweeper_params['QI'] = ['LU']
sweeper_params['initial_guess'] = 'zero'
# initialize problem parameters
problem_params = dict()
problem_params['freq'] = -1 # frequency for the test value
problem_params['nvars'] = [127, 63
] # number of degrees of freedom for each level
# initialize step parameters
step_params = dict()
step_params['maxiter'] = 50
# initialize space transfer parameters
space_transfer_params = dict()
space_transfer_params['rorder'] = 2
space_transfer_params['iorder'] = 2
space_transfer_params['periodic'] = False
# initialize controller parameters
controller_params = dict()
controller_params['logger_level'] = 30
# fill description dictionary for easy step instantiation
description = dict()
description['problem_class'] = heat1d # pass problem class
description[
'sweeper_class'] = generic_implicit # pass sweeper (see part B)
description['sweeper_params'] = sweeper_params # pass sweeper parameters
description['level_params'] = level_params # pass level parameters
description['step_params'] = step_params # pass step parameters
description[
'space_transfer_class'] = mesh_to_mesh # pass spatial transfer class
description[
'space_transfer_params'] = space_transfer_params # pass paramters for spatial transfer
# set time parameters
t0 = 0.0
Tend = 4 * level_params['dt']
# set up number of parallel time-steps to run PFASST with
num_proc = 4
results = dict()
for i in range(-3, 10):
ratio = level_params['dt'] / (1.0 /
(problem_params['nvars'][0] + 1))**2
problem_params['nu'] = 10.0**i / ratio # diffusion coefficient
description[
'problem_params'] = problem_params # pass problem parameters
out = 'Working on c = %6.4e' % problem_params['nu']
print(out)
cfl = ratio * problem_params['nu']
out = ' CFL number: %4.2e' % cfl
print(out)
# instantiate controller
controller = controller_nonMPI(num_procs=num_proc,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
print(out)
if nsweeps == 3 and (i == -3 or i == 9):
assert np.mean(niters) <= 2, 'ERROR: too much iterations for diffusive asymptotics, got %s' \
% np.mean(niters)
results[cfl] = np.mean(niters)
fname = 'data/results_conv_diffusion_NS' + str(nsweeps) + '.pkl'
file = open(fname, 'wb')
pickle.dump(results, file)
file.close()
assert os.path.isfile(fname), 'ERROR: pickle did not create file'
def run_simulation(prob=None):
"""
Routine to run the simulation of a second order problem
Args:
prob (str): name of the problem
"""
if prob == 'outer_solar_system':
description, controller_params = setup_outer_solar_system()
# set time parameters
t0 = 0.0
Tend = 10000.0
num_procs = 100
maxmeaniter = 6.0
elif prob == 'full_solar_system':
description, controller_params = setup_full_solar_system()
# set time parameters
t0 = 0.0
Tend = 1000.0
num_procs = 100
maxmeaniter = 19.0
else:
raise NotImplemented('Problem type not implemented, got %s' % prob)
f = open(prob + '_out.txt', 'w')
out = 'Running ' + prob + ' problem with %s processors...' % num_procs
f.write(out + '\n')
print(out)
# instantiate the controller
controller = controller_nonMPI(num_procs=num_procs,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t=t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# filter statistics by type (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
# for item in iter_counts:
# out = 'Number of iterations for time %4.2f: %2i' % item
# f.write(out)
# print(out)
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
f.write(out + '\n')
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(niters)
f.write(out + '\n')
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
f.write(out + '\n')
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (float(
np.std(niters)), float(np.var(niters)))
f.write(out + '\n')
print(out)
f.close()
assert np.mean(
niters
) <= maxmeaniter, 'Mean number of iterations is too high, got %s' % np.mean(
niters)
fname = 'data/' + prob + '.dat'
f = open(fname, 'wb')
dill.dump(stats, f)
f.close()
assert os.path.isfile(fname), 'Run for %s did not create stats file' % prob
def run_SDC_variant(variant=None, inexact=False):
"""
Routine to run particular SDC variant
Args:
variant (str): string describing the variant
inexact (bool): flag to use inexact nonlinear solve (or nor)
Returns:
results and statistics of the run
"""
# load (incomplete) default parameters
description, controller_params = setup_parameters()
# add stuff based on variant
if variant == 'fully-implicit':
description['problem_class'] = allencahn_periodic_fullyimplicit
# description['problem_class'] = allencahn_front_finel
description['sweeper_class'] = generic_implicit
if inexact:
description['problem_params']['newton_maxiter'] = 1
elif variant == 'semi-implicit':
description['problem_class'] = allencahn_periodic_semiimplicit
description['sweeper_class'] = imex_1st_order
if inexact:
description['problem_params']['lin_maxiter'] = 10
elif variant == 'multi-implicit':
description['problem_class'] = allencahn_periodic_multiimplicit
description['sweeper_class'] = multi_implicit
if inexact:
description['problem_params']['newton_maxiter'] = 1
description['problem_params']['lin_maxiter'] = 10
# elif variant == 'multi-implicit_v2':
# description['problem_class'] = allencahn_multiimplicit_v2
# description['sweeper_class'] = multi_implicit
# if inexact:
# description['problem_params']['newton_maxiter'] = 1
else:
raise NotImplemented('Wrong variant specified, got %s' % variant)
if inexact:
out = 'Working on inexact %s variant...' % variant
else:
out = 'Working on exact %s variant...' % variant
print(out)
# setup parameters "in time"
t0 = 0
Tend = description['level_params']['dt']
# instantiate controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# plt_helper.plt.plot(uinit.values)
# plt_helper.savefig('uinit', save_pdf=False, save_pgf=False, save_png=True)
#
# uex = P.u_exact(Tend)
# plt_helper.plt.plot(uex.values)
# plt_helper.savefig('uex', save_pdf=False, save_pgf=False, save_png=True)
# exit()
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
plt_helper.plt.plot(uend.values)
plt_helper.savefig('uend', save_pdf=False, save_pgf=False, save_png=True)
# exit()
# filter statistics by variant (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(niters)
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (float(
np.std(niters)), float(np.var(niters)))
print(out)
print(' Iteration count (nonlinear/linear): %i / %i' %
(P.newton_itercount, P.lin_itercount))
print(' Mean Iteration count per call: %4.2f / %4.2f' %
(P.newton_itercount / max(P.newton_ncalls, 1),
P.lin_itercount / max(P.lin_ncalls, 1)))
timing = sort_stats(filter_stats(stats, type='timing_run'), sortby='time')
print('Time to solution: %6.4f sec.' % timing[0][1])
print()
return stats
def run_SDC_variant(variant=None, inexact=False):
"""
Routine to run particular SDC variant
Args:
variant (str): string describing the variant
inexact (bool): flag to use inexact nonlinear solve (or nor)
Returns:
timing (float)
niter (float)
"""
# load (incomplete) default parameters
description, controller_params = setup_parameters()
# add stuff based on variant
if variant == 'fully-implicit':
description['problem_class'] = petsc_fisher_fullyimplicit
description['sweeper_class'] = generic_implicit
elif variant == 'semi-implicit':
description['problem_class'] = petsc_fisher_semiimplicit
description['sweeper_class'] = imex_1st_order
elif variant == 'multi-implicit':
description['problem_class'] = petsc_fisher_multiimplicit
description['sweeper_class'] = multi_implicit
else:
raise NotImplemented('Wrong variant specified, got %s' % variant)
if inexact:
description['problem_params']['nlsol_maxiter'] = 1
out = 'Working on inexact %s variant...' % variant
else:
out = 'Working on exact %s variant...' % variant
print(out)
# set time parameters
t0 = 0.0
Tend = 1.0
# instantiate controller
controller = controller_nonMPI(num_procs=1,
controller_params=controller_params,
description=description)
# get initial values on finest level
P = controller.MS[0].levels[0].prob
uinit = P.u_exact(t0)
# call main function to get things done...
uend, stats = controller.run(u0=uinit, t0=t0, Tend=Tend)
# compute exact solution and compare
uex = P.u_exact(Tend)
err = abs(uex - uend)
# filter statistics by variant (number of iterations)
filtered_stats = filter_stats(stats, type='niter')
# convert filtered statistics to list of iterations count, sorted by process
iter_counts = sort_stats(filtered_stats, sortby='time')
# compute and print statistics
niters = np.array([item[1] for item in iter_counts])
out = ' Mean number of iterations: %4.2f' % np.mean(niters)
print(out)
out = ' Range of values for number of iterations: %2i ' % np.ptp(niters)
print(out)
out = ' Position of max/min number of iterations: %2i -- %2i' % \
(int(np.argmax(niters)), int(np.argmin(niters)))
print(out)
out = ' Std and var for number of iterations: %4.2f -- %4.2f' % (float(
np.std(niters)), float(np.var(niters)))
print(out)
print('Iteration count (nonlinear/linear): %i / %i' %
(P.snes_itercount, P.ksp_itercount))
print('Mean Iteration count per call: %4.2f / %4.2f' %
(P.snes_itercount / max(P.snes_ncalls, 1),
P.ksp_itercount / max(P.ksp_ncalls, 1)))
timing = sort_stats(filter_stats(stats, type='timing_run'), sortby='time')
print('Time to solution: %6.4f sec.' % timing[0][1])
print('Error vs. PDE solution: %6.4e' % err)
print()
assert err < 9.2E-05, 'ERROR: variant %s did not match error tolerance, got %s' % (
variant, err)
assert np.mean(
niters
) <= 10, 'ERROR: number of iterations is too high, got %s' % np.mean(
niters)
return timing[0][1], np.mean(niters)
