Beispiel #1
0
def hapod_demo(args):
    args['--grid'] = int(args['--grid'])
    args['--nt'] = int(args['--nt'])
    args['--omega'] = float(args['--omega'])
    args['--procs'] = int(args['--procs'])
    args['--snap'] = int(args['--snap'])
    args['--threads'] = int(args['--threads'])
    args['TOL'] = float(args['TOL'])
    args['DIST'] = int(args['DIST'])
    args['INC'] = int(args['INC'])
    assert args['--procs'] == 0 or args['--threads'] == 0

    tol = args['TOL']
    omega = args['--omega']
    executor = ProcessPoolExecutor(args['--procs']) if args['--procs'] > 0 else \
        ThreadPoolExecutor(args['--threads']) if args['--threads'] > 0 else \
        None

    p = burgers_problem_2d()
    d, data = discretize_instationary_fv(p, grid_type=RectGrid, diameter=np.sqrt(2)/args['--grid'], nt=args['--nt'])

    U = d.solution_space.empty()
    for mu in d.parameter_space.sample_randomly(args['--snap']):
        U.append(d.solve(mu))

    tic = time()
    pod_modes = pod(U, l2_err=tol * np.sqrt(len(U)), product=d.l2_product, check=False)[0]
    pod_time = time() - tic

    tic = time()
    dist_modes = dist_vectorarray_hapod(args['DIST'], U, tol, omega, product=d.l2_product, executor=executor)[0]
    dist_time = time() - tic

    tic = time()
    inc_modes = inc_vectorarray_hapod(args['INC'], U, tol, omega, product=d.l2_product)[0]
    inc_time = time() - tic

    print('Snapshot matrix: {} x {}'.format(U.dim, len(U)))
    print(format_table([
        ['Method', 'Error', 'Modes', 'Time'],
        ['POD', np.linalg.norm(d.l2_norm(U-pod_modes.lincomb(d.l2_product.apply2(U, pod_modes)))/np.sqrt(len(U))),
         len(pod_modes), pod_time],
        ['DIST HAPOD', np.linalg.norm(d.l2_norm(U-dist_modes.lincomb(d.l2_product.apply2(U, dist_modes)))/np.sqrt(len(U))),
         len(dist_modes), dist_time],
        ['INC HAPOD', np.linalg.norm(d.l2_norm(U-inc_modes.lincomb(d.l2_product.apply2(U, inc_modes)))/np.sqrt(len(U))),
         len(inc_modes), inc_time]]
    ))
Beispiel #2
0
def burgers_demo(args):
    args['--grid'] = int(args['--grid'])
    args['--grid-type'] = args['--grid-type'].lower()
    assert args['--grid-type'] in ('rect', 'tria')
    args['--initial-data'] = args['--initial-data'].lower()
    assert args['--initial-data'] in ('sin', 'bump')
    args['--lxf-lambda'] = float(args['--lxf-lambda'])
    args['--nt'] = int(args['--nt'])
    args['--not-periodic'] = bool(args['--not-periodic'])
    args['--num-flux'] = args['--num-flux'].lower()
    assert args['--num-flux'] in ('lax_friedrichs', 'engquist_osher', 'simplified_engquist_osher')
    args['--vx'] = float(args['--vx'])
    args['--vy'] = float(args['--vy'])
    args['EXP'] = float(args['EXP'])

    print('Setup Problem ...')
    grid_type_map = {'rect': RectGrid, 'tria': TriaGrid}
    domain_discretizer = partial(discretize_domain_default, grid_type=grid_type_map[args['--grid-type']])
    problem = burgers_problem_2d(vx=args['--vx'], vy=args['--vy'], initial_data_type=args['--initial-data'],
                                 parameter_range=(0, 1e42), torus=not args['--not-periodic'])

    print('Discretize ...')
    if args['--grid-type'] == 'rect':
        args['--grid'] *= 1. / m.sqrt(2)
    discretization, data = discretize_instationary_fv(
        problem, diameter=1. / args['--grid'],
        num_flux=args['--num-flux'], lxf_lambda=args['--lxf-lambda'],
        nt=args['--nt'], domain_discretizer=domain_discretizer
    )
    print(discretization.operator.grid)

    print('The parameter type is {}'.format(discretization.parameter_type))

    mu = args['EXP']
    # U = discretization.solve(0)
    print('Solving for exponent = {} ... '.format(mu))
    sys.stdout.flush()
    # pr = cProfile.Profile()
    # pr.enable()
    tic = time.time()
    U = discretization.solve(mu)
    # pr.disable()
    print('Solving took {}s'.format(time.time() - tic))
    # pr.dump_stats('bla')
    discretization.visualize(U)
Beispiel #3
0
def burgers_demo(args):
    args['--grid'] = int(args['--grid'])
    args['--grid-type'] = args['--grid-type'].lower()
    assert args['--grid-type'] in ('rect', 'tria')
    args['--initial-data'] = args['--initial-data'].lower()
    assert args['--initial-data'] in ('sin', 'bump')
    args['--lxf-lambda'] = float(args['--lxf-lambda'])
    args['--nt'] = int(args['--nt'])
    args['--not-periodic'] = bool(args['--not-periodic'])
    args['--num-flux'] = args['--num-flux'].lower()
    assert args['--num-flux'] in ('lax_friedrichs', 'engquist_osher',
                                  'simplified_engquist_osher')
    args['--vx'] = float(args['--vx'])
    args['--vy'] = float(args['--vy'])
    args['EXP'] = float(args['EXP'])

    print('Setup Problem ...')
    problem = burgers_problem_2d(vx=args['--vx'],
                                 vy=args['--vy'],
                                 initial_data_type=args['--initial-data'],
                                 parameter_range=(0, 1e42),
                                 torus=not args['--not-periodic'])

    print('Discretize ...')
    if args['--grid-type'] == 'rect':
        args['--grid'] *= 1. / m.sqrt(2)
    discretization, data = discretize_instationary_fv(
        problem,
        diameter=1. / args['--grid'],
        grid_type=RectGrid if args['--grid-type'] == 'rect' else TriaGrid,
        num_flux=args['--num-flux'],
        lxf_lambda=args['--lxf-lambda'],
        nt=args['--nt'])
    print(discretization.operator.grid)

    print('The parameter type is {}'.format(discretization.parameter_type))

    mu = args['EXP']
    print('Solving for exponent = {} ... '.format(mu))
    sys.stdout.flush()
    tic = time.time()
    U = discretization.solve(mu)
    print('Solving took {}s'.format(time.time() - tic))
    discretization.visualize(U)
Beispiel #4
0
def burgers_demo(args):
    args['--grid'] = int(args['--grid'])
    args['--grid-type'] = args['--grid-type'].lower()
    assert args['--grid-type'] in ('rect', 'tria')
    args['--initial-data'] = args['--initial-data'].lower()
    assert args['--initial-data'] in ('sin', 'bump')
    args['--lxf-lambda'] = float(args['--lxf-lambda'])
    args['--nt'] = int(args['--nt'])
    args['--not-periodic'] = bool(args['--not-periodic'])
    args['--num-flux'] = args['--num-flux'].lower()
    assert args['--num-flux'] in ('lax_friedrichs', 'engquist_osher', 'simplified_engquist_osher')
    args['--vx'] = float(args['--vx'])
    args['--vy'] = float(args['--vy'])
    args['EXP'] = float(args['EXP'])

    print('Setup Problem ...')
    problem = burgers_problem_2d(vx=args['--vx'], vy=args['--vy'], initial_data_type=args['--initial-data'],
                                 parameter_range=(0, 1e42), torus=not args['--not-periodic'])

    print('Discretize ...')
    if args['--grid-type'] == 'rect':
        args['--grid'] *= 1. / math.sqrt(2)
    m, data = discretize_instationary_fv(
        problem,
        diameter=1. / args['--grid'],
        grid_type=RectGrid if args['--grid-type'] == 'rect' else TriaGrid,
        num_flux=args['--num-flux'],
        lxf_lambda=args['--lxf-lambda'],
        nt=args['--nt']
    )
    print(m.operator.grid)

    print(f'The parameter type is {m.parameter_type}')

    mu = args['EXP']
    print(f'Solving for exponent = {mu} ... ')
    sys.stdout.flush()
    tic = time.time()
    U = m.solve(mu)
    print(f'Solving took {time.time()-tic}s')
    m.visualize(U)
Beispiel #5
0
from itertools import product

import pytest
from pkg_resources import resource_filename

from pymor.discretizers.cg import discretize_stationary_cg
from pymor.discretizers.fv import discretize_instationary_fv
from pymor.discretizers.disk import discretize_stationary_from_disk, discretize_instationary_from_disk
from pymortests.fixtures.analyticalproblem import (picklable_thermalblock_problems, non_picklable_thermalblock_problems,
                                                   burgers_problems)


picklable_discretizaion_generators = \
        [lambda p=p, d=d: discretize_stationary_cg(p, diameter=d)[0]
         for p, d in product(picklable_thermalblock_problems, [1./50., 1./100.])] + \
        [lambda p=p, d=d: discretize_instationary_fv(p, diameter=d, nt=100)[0]
         for p, d in product(burgers_problems, [1./10., 1./15.])] + \
        [lambda p=p: discretize_stationary_from_disk(parameter_file=p)
         for p in (resource_filename('pymortests', 'testdata/parameter_stationary.ini'),)] + \
        [lambda p=p: discretize_instationary_from_disk(parameter_file=p)
         for p in (resource_filename('pymortests', 'testdata/parameter_instationary.ini'),)]


non_picklable_discretization_generators = \
        [lambda p=p, d=d: discretize_stationary_cg(p, diameter=d)[0]
         for p, d in product(non_picklable_thermalblock_problems, [1./20., 1./30.])]


discretization_generators = picklable_discretizaion_generators + non_picklable_discretization_generators

Beispiel #6
0
def main(args):
    args = docopt(__doc__, args)
    args['--cache-region'] = args['--cache-region'].lower()
    args['--grid'] = int(args['--grid'])
    args['--grid-type'] = args['--grid-type'].lower()
    assert args['--grid-type'] in ('rect', 'tria')
    args['--initial-data'] = args['--initial-data'].lower()
    assert args['--initial-data'] in ('sin', 'bump')
    args['--lxf-lambda'] = float(args['--lxf-lambda'])
    args['--nt'] = int(args['--nt'])
    args['--not-periodic'] = bool(args['--not-periodic'])
    args['--num-flux'] = args['--num-flux'].lower()
    assert args['--num-flux'] in ('lax_friedrichs', 'engquist_osher')
    args['--plot-error-landscape-N'] = int(args['--plot-error-landscape-N'])
    args['--plot-error-landscape-M'] = int(args['--plot-error-landscape-M'])
    args['--test'] = int(args['--test'])
    args['--vx'] = float(args['--vx'])
    args['--vy'] = float(args['--vy'])
    args['--ipython-engines'] = int(args['--ipython-engines'])
    args['EXP_MIN'] = int(args['EXP_MIN'])
    args['EXP_MAX'] = int(args['EXP_MAX'])
    args['EI_SNAPSHOTS'] = int(args['EI_SNAPSHOTS'])
    args['EISIZE'] = int(args['EISIZE'])
    args['SNAPSHOTS'] = int(args['SNAPSHOTS'])
    args['RBSIZE'] = int(args['RBSIZE'])

    print('Setup Problem ...')
    problem = burgers_problem_2d(vx=args['--vx'], vy=args['--vy'], initial_data_type=args['--initial-data'],
                                 parameter_range=(args['EXP_MIN'], args['EXP_MAX']), torus=not args['--not-periodic'])

    print('Discretize ...')
    if args['--grid-type'] == 'rect':
        args['--grid'] *= 1. / m.sqrt(2)
    d, _ = discretize_instationary_fv(
        problem,
        diameter=1. / args['--grid'],
        grid_type=RectGrid if args['--grid-type'] == 'rect' else TriaGrid,
        num_flux=args['--num-flux'],
        lxf_lambda=args['--lxf-lambda'],
        nt=args['--nt']
    )

    if args['--cache-region'] != 'none':
        d.enable_caching(args['--cache-region'])

    print(d.operator.grid)

    print('The parameter type is {}'.format(d.parameter_type))

    if args['--plot-solutions']:
        print('Showing some solutions')
        Us = ()
        legend = ()
        for mu in d.parameter_space.sample_uniformly(4):
            print('Solving for exponent = {} ... '.format(mu['exponent']))
            sys.stdout.flush()
            Us = Us + (d.solve(mu),)
            legend = legend + ('exponent: {}'.format(mu['exponent']),)
        d.visualize(Us, legend=legend, title='Detailed Solutions', block=True)

    pool = new_parallel_pool(ipython_num_engines=args['--ipython-engines'], ipython_profile=args['--ipython-profile'])
    ei_d, ei_data = interpolate_operators(d, ['operator'],
                                          d.parameter_space.sample_uniformly(args['EI_SNAPSHOTS']),  # NOQA
                                          error_norm=d.l2_norm,
                                          max_interpolation_dofs=args['EISIZE'],
                                          pool=pool)

    if args['--plot-ei-err']:
        print('Showing some EI errors')
        ERRs = ()
        legend = ()
        for mu in d.parameter_space.sample_randomly(2):
            print('Solving for exponent = \n{} ... '.format(mu['exponent']))
            sys.stdout.flush()
            U = d.solve(mu)
            U_EI = ei_d.solve(mu)
            ERR = U - U_EI
            ERRs = ERRs + (ERR,)
            legend = legend + ('exponent: {}'.format(mu['exponent']),)
            print('Error: {}'.format(np.max(d.l2_norm(ERR))))
        d.visualize(ERRs, legend=legend, title='EI Errors', separate_colorbars=True)

        print('Showing interpolation DOFs ...')
        U = np.zeros(U.dim)
        dofs = ei_d.operator.interpolation_dofs
        U[dofs] = np.arange(1, len(dofs) + 1)
        U[ei_d.operator.source_dofs] += int(len(dofs)/2)
        d.visualize(d.solution_space.make_array(U),
                                 title='Interpolation DOFs')

    print('RB generation ...')

    reductor = GenericRBReductor(ei_d)

    greedy_data = greedy(d, reductor, d.parameter_space.sample_uniformly(args['SNAPSHOTS']),
                         use_estimator=False, error_norm=lambda U: np.max(d.l2_norm(U)),
                         extension_params={'method': 'pod'}, max_extensions=args['RBSIZE'],
                         pool=pool)

    rd = greedy_data['rd']

    print('\nSearching for maximum error on random snapshots ...')

    tic = time.time()

    mus = d.parameter_space.sample_randomly(args['--test'])

    def error_analysis(N, M):
        print('N = {}, M = {}: '.format(N, M), end='')
        rd = reductor.reduce(N)
        rd = rd.with_(operator=rd.operator.with_cb_dim(M))
        l2_err_max = -1
        mumax = None
        for mu in mus:
            print('.', end='')
            sys.stdout.flush()
            u = rd.solve(mu)
            URB = reductor.reconstruct(u)
            U = d.solve(mu)
            l2_err = np.max(d.l2_norm(U - URB))
            l2_err = np.inf if not np.isfinite(l2_err) else l2_err
            if l2_err > l2_err_max:
                l2_err_max = l2_err
                mumax = mu
        print()
        return l2_err_max, mumax
    error_analysis = np.frompyfunc(error_analysis, 2, 2)

    real_rb_size = len(reductor.RB)
    real_cb_size = len(ei_data['basis'])
    if args['--plot-error-landscape']:
        N_count = min(real_rb_size - 1, args['--plot-error-landscape-N'])
        M_count = min(real_cb_size - 1, args['--plot-error-landscape-M'])
        Ns = np.linspace(1, real_rb_size, N_count).astype(np.int)
        Ms = np.linspace(1, real_cb_size, M_count).astype(np.int)
    else:
        Ns = np.array([real_rb_size])
        Ms = np.array([real_cb_size])

    N_grid, M_grid = np.meshgrid(Ns, Ms)

    errs, err_mus = error_analysis(N_grid, M_grid)
    errs = errs.astype(np.float)

    l2_err_max = errs[-1, -1]
    mumax = err_mus[-1, -1]
    toc = time.time()
    t_est = toc - tic

    print('''
    *** RESULTS ***

    Problem:
       parameter range:                    ({args[EXP_MIN]}, {args[EXP_MAX]})
       h:                                  sqrt(2)/{args[--grid]}
       grid-type:                          {args[--grid-type]}
       initial-data:                       {args[--initial-data]}
       lxf-lambda:                         {args[--lxf-lambda]}
       nt:                                 {args[--nt]}
       not-periodic:                       {args[--not-periodic]}
       num-flux:                           {args[--num-flux]}
       (vx, vy):                           ({args[--vx]}, {args[--vy]})

    Greedy basis generation:
       number of ei-snapshots:             {args[EI_SNAPSHOTS]}
       prescribed collateral basis size:   {args[EISIZE]}
       actual collateral basis size:       {real_cb_size}
       number of snapshots:                {args[SNAPSHOTS]}
       prescribed basis size:              {args[RBSIZE]}
       actual basis size:                  {real_rb_size}
       elapsed time:                       {greedy_data[time]}

    Stochastic error estimation:
       number of samples:                  {args[--test]}
       maximal L2-error:                   {l2_err_max}  (mu = {mumax})
       elapsed time:                       {t_est}
    '''.format(**locals()))

    sys.stdout.flush()
    if args['--plot-error-landscape']:
        import matplotlib.pyplot as plt
        import mpl_toolkits.mplot3d             # NOQA
        fig = plt.figure()
        ax = fig.add_subplot(111, projection='3d')
        # we have to rescale the errors since matplotlib does not support logarithmic scales on 3d plots
        # https://github.com/matplotlib/matplotlib/issues/209
        surf = ax.plot_surface(M_grid, N_grid, np.log(np.minimum(errs, 1)) / np.log(10),
                               rstride=1, cstride=1, cmap='jet')
        plt.show()
    if args['--plot-err']:
        U = d.solve(mumax)
        URB = reductor.reconstruct(rd.solve(mumax))
        d.visualize((U, URB, U - URB), legend=('Detailed Solution', 'Reduced Solution', 'Error'),
                    title='Maximum Error Solution', separate_colorbars=True)

    return ei_data, greedy_data
Beispiel #7
0
def hapod_demo(args):
    args['--grid'] = int(args['--grid'])
    args['--nt'] = int(args['--nt'])
    args['--omega'] = float(args['--omega'])
    args['--procs'] = int(args['--procs'])
    args['--snap'] = int(args['--snap'])
    args['--threads'] = int(args['--threads'])
    args['TOL'] = float(args['TOL'])
    args['DIST'] = int(args['DIST'])
    args['INC'] = int(args['INC'])
    assert args['--procs'] == 0 or args['--threads'] == 0

    tol = args['TOL']
    omega = args['--omega']
    executor = ProcessPoolExecutor(args['--procs']) if args['--procs'] > 0 else \
        ThreadPoolExecutor(args['--threads']) if args['--threads'] > 0 else \
        None

    p = burgers_problem_2d()
    m, data = discretize_instationary_fv(p,
                                         grid_type=RectGrid,
                                         diameter=np.sqrt(2) / args['--grid'],
                                         nt=args['--nt'])

    U = m.solution_space.empty()
    for mu in m.parameter_space.sample_randomly(args['--snap']):
        U.append(m.solve(mu))

    tic = time()
    pod_modes = pod(U,
                    l2_err=tol * np.sqrt(len(U)),
                    product=m.l2_product,
                    check=False)[0]
    pod_time = time() - tic

    tic = time()
    dist_modes = dist_vectorarray_hapod(args['DIST'],
                                        U,
                                        tol,
                                        omega,
                                        product=m.l2_product,
                                        executor=executor)[0]
    dist_time = time() - tic

    tic = time()
    inc_modes = inc_vectorarray_hapod(args['INC'],
                                      U,
                                      tol,
                                      omega,
                                      product=m.l2_product)[0]
    inc_time = time() - tic

    print(f'Snapshot matrix: {U.dim} x {len(U)}')
    print(
        format_table([
            ['Method', 'Error', 'Modes', 'Time'],
            [
                'POD',
                np.linalg.norm(
                    m.l2_norm(U - pod_modes.lincomb(
                        m.l2_product.apply2(U, pod_modes))) / np.sqrt(len(U))),
                len(pod_modes), pod_time
            ],
            [
                'DIST HAPOD',
                np.linalg.norm(
                    m.l2_norm(U - dist_modes.lincomb(
                        m.l2_product.apply2(U, dist_modes))) /
                    np.sqrt(len(U))),
                len(dist_modes), dist_time
            ],
            [
                'INC HAPOD',
                np.linalg.norm(
                    m.l2_norm(U - inc_modes.lincomb(
                        m.l2_product.apply2(U, inc_modes))) / np.sqrt(len(U))),
                len(inc_modes), inc_time
            ]
        ]))
Beispiel #8
0
def main(args):
    args = docopt(__doc__, args)
    args['--cache-region'] = args['--cache-region'].lower()
    args['--ei-alg'] = args['--ei-alg'].lower()
    assert args['--ei-alg'] in ('ei_greedy', 'deim')
    args['--grid'] = int(args['--grid'])
    args['--grid-type'] = args['--grid-type'].lower()
    assert args['--grid-type'] in ('rect', 'tria')
    args['--initial-data'] = args['--initial-data'].lower()
    assert args['--initial-data'] in ('sin', 'bump')
    args['--lxf-lambda'] = float(args['--lxf-lambda'])
    args['--nt'] = int(args['--nt'])
    args['--not-periodic'] = bool(args['--not-periodic'])
    args['--num-flux'] = args['--num-flux'].lower()
    assert args['--num-flux'] in ('lax_friedrichs', 'engquist_osher')
    args['--plot-error-landscape-N'] = int(args['--plot-error-landscape-N'])
    args['--plot-error-landscape-M'] = int(args['--plot-error-landscape-M'])
    args['--test'] = int(args['--test'])
    args['--vx'] = float(args['--vx'])
    args['--vy'] = float(args['--vy'])
    args['--ipython-engines'] = int(args['--ipython-engines'])
    args['EXP_MIN'] = int(args['EXP_MIN'])
    args['EXP_MAX'] = int(args['EXP_MAX'])
    args['EI_SNAPSHOTS'] = int(args['EI_SNAPSHOTS'])
    args['EISIZE'] = int(args['EISIZE'])
    args['SNAPSHOTS'] = int(args['SNAPSHOTS'])
    args['RBSIZE'] = int(args['RBSIZE'])

    print('Setup Problem ...')
    problem = burgers_problem_2d(vx=args['--vx'],
                                 vy=args['--vy'],
                                 initial_data_type=args['--initial-data'],
                                 parameter_range=(args['EXP_MIN'],
                                                  args['EXP_MAX']),
                                 torus=not args['--not-periodic'])

    print('Discretize ...')
    if args['--grid-type'] == 'rect':
        args['--grid'] *= 1. / math.sqrt(2)
    fom, _ = discretize_instationary_fv(
        problem,
        diameter=1. / args['--grid'],
        grid_type=RectGrid if args['--grid-type'] == 'rect' else TriaGrid,
        num_flux=args['--num-flux'],
        lxf_lambda=args['--lxf-lambda'],
        nt=args['--nt'])

    if args['--cache-region'] != 'none':
        fom.enable_caching(args['--cache-region'])

    print(fom.operator.grid)

    print(f'The parameter type is {fom.parameter_type}')

    if args['--plot-solutions']:
        print('Showing some solutions')
        Us = ()
        legend = ()
        for mu in fom.parameter_space.sample_uniformly(4):
            print(f"Solving for exponent = {mu['exponent']} ... ")
            sys.stdout.flush()
            Us = Us + (fom.solve(mu), )
            legend = legend + (f"exponent: {mu['exponent']}", )
        fom.visualize(Us,
                      legend=legend,
                      title='Detailed Solutions',
                      block=True)

    pool = new_parallel_pool(ipython_num_engines=args['--ipython-engines'],
                             ipython_profile=args['--ipython-profile'])
    eim, ei_data = interpolate_operators(
        fom,
        ['operator'],
        fom.parameter_space.sample_uniformly(args['EI_SNAPSHOTS']),  # NOQA
        error_norm=fom.l2_norm,
        product=fom.l2_product,
        max_interpolation_dofs=args['EISIZE'],
        alg=args['--ei-alg'],
        pool=pool)

    if args['--plot-ei-err']:
        print('Showing some EI errors')
        ERRs = ()
        legend = ()
        for mu in fom.parameter_space.sample_randomly(2):
            print(f"Solving for exponent = \n{mu['exponent']} ... ")
            sys.stdout.flush()
            U = fom.solve(mu)
            U_EI = eim.solve(mu)
            ERR = U - U_EI
            ERRs = ERRs + (ERR, )
            legend = legend + (f"exponent: {mu['exponent']}", )
            print(f'Error: {np.max(fom.l2_norm(ERR))}')
        fom.visualize(ERRs,
                      legend=legend,
                      title='EI Errors',
                      separate_colorbars=True)

        print('Showing interpolation DOFs ...')
        U = np.zeros(U.dim)
        dofs = eim.operator.interpolation_dofs
        U[dofs] = np.arange(1, len(dofs) + 1)
        U[eim.operator.source_dofs] += int(len(dofs) / 2)
        fom.visualize(fom.solution_space.make_array(U),
                      title='Interpolation DOFs')

    print('RB generation ...')

    reductor = InstationaryRBReductor(eim)

    greedy_data = rb_greedy(fom,
                            reductor,
                            fom.parameter_space.sample_uniformly(
                                args['SNAPSHOTS']),
                            use_estimator=False,
                            error_norm=lambda U: np.max(fom.l2_norm(U)),
                            extension_params={'method': 'pod'},
                            max_extensions=args['RBSIZE'],
                            pool=pool)

    rom = greedy_data['rom']

    print('\nSearching for maximum error on random snapshots ...')

    tic = time.time()

    mus = fom.parameter_space.sample_randomly(args['--test'])

    def error_analysis(N, M):
        print(f'N = {N}, M = {M}: ', end='')
        rom = reductor.reduce(N)
        rom = rom.with_(operator=rom.operator.with_cb_dim(M))
        l2_err_max = -1
        mumax = None
        for mu in mus:
            print('.', end='')
            sys.stdout.flush()
            u = rom.solve(mu)
            URB = reductor.reconstruct(u)
            U = fom.solve(mu)
            l2_err = np.max(fom.l2_norm(U - URB))
            l2_err = np.inf if not np.isfinite(l2_err) else l2_err
            if l2_err > l2_err_max:
                l2_err_max = l2_err
                mumax = mu
        print()
        return l2_err_max, mumax

    error_analysis = np.frompyfunc(error_analysis, 2, 2)

    real_rb_size = len(reductor.bases['RB'])
    real_cb_size = len(ei_data['basis'])
    if args['--plot-error-landscape']:
        N_count = min(real_rb_size - 1, args['--plot-error-landscape-N'])
        M_count = min(real_cb_size - 1, args['--plot-error-landscape-M'])
        Ns = np.linspace(1, real_rb_size, N_count).astype(np.int)
        Ms = np.linspace(1, real_cb_size, M_count).astype(np.int)
    else:
        Ns = np.array([real_rb_size])
        Ms = np.array([real_cb_size])

    N_grid, M_grid = np.meshgrid(Ns, Ms)

    errs, err_mus = error_analysis(N_grid, M_grid)
    errs = errs.astype(np.float)

    l2_err_max = errs[-1, -1]
    mumax = err_mus[-1, -1]
    toc = time.time()
    t_est = toc - tic

    print('''
    *** RESULTS ***

    Problem:
       parameter range:                    ({args[EXP_MIN]}, {args[EXP_MAX]})
       h:                                  sqrt(2)/{args[--grid]}
       grid-type:                          {args[--grid-type]}
       initial-data:                       {args[--initial-data]}
       lxf-lambda:                         {args[--lxf-lambda]}
       nt:                                 {args[--nt]}
       not-periodic:                       {args[--not-periodic]}
       num-flux:                           {args[--num-flux]}
       (vx, vy):                           ({args[--vx]}, {args[--vy]})

    Greedy basis generation:
       number of ei-snapshots:             {args[EI_SNAPSHOTS]}
       prescribed collateral basis size:   {args[EISIZE]}
       actual collateral basis size:       {real_cb_size}
       number of snapshots:                {args[SNAPSHOTS]}
       prescribed basis size:              {args[RBSIZE]}
       actual basis size:                  {real_rb_size}
       elapsed time:                       {greedy_data[time]}

    Stochastic error estimation:
       number of samples:                  {args[--test]}
       maximal L2-error:                   {l2_err_max}  (mu = {mumax})
       elapsed time:                       {t_est}
    '''.format(**locals()))

    sys.stdout.flush()
    if args['--plot-error-landscape']:
        import matplotlib.pyplot as plt
        import mpl_toolkits.mplot3d  # NOQA
        fig = plt.figure()
        ax = fig.add_subplot(111, projection='3d')
        # we have to rescale the errors since matplotlib does not support logarithmic scales on 3d plots
        # https://github.com/matplotlib/matplotlib/issues/209
        surf = ax.plot_surface(M_grid,
                               N_grid,
                               np.log(np.minimum(errs, 1)) / np.log(10),
                               rstride=1,
                               cstride=1,
                               cmap='jet')
        plt.show()
    if args['--plot-err']:
        U = fom.solve(mumax)
        URB = reductor.reconstruct(rom.solve(mumax))
        fom.visualize(
            (U, URB, U - URB),
            legend=('Detailed Solution', 'Reduced Solution', 'Error'),
            title='Maximum Error Solution',
            separate_colorbars=True)

    return ei_data, greedy_data
Beispiel #9
0
from itertools import product

import pytest
from pkg_resources import resource_filename

from pymor.discretizers.cg import discretize_stationary_cg
from pymor.discretizers.fv import discretize_instationary_fv
from pymor.discretizers.disk import discretize_stationary_from_disk, discretize_instationary_from_disk
from pymortests.fixtures.analyticalproblem import (picklable_thermalblock_problems, non_picklable_thermalblock_problems,
                                                   burgers_problems)


picklable_discretizaion_generators = \
        [lambda p=p, d=d: discretize_stationary_cg(p, diameter=d)[0]
         for p, d in product(picklable_thermalblock_problems, [1./50., 1./100.])] + \
        [lambda p=p, d=d: discretize_instationary_fv(p, diameter=d, nt=100)[0]
         for p, d in product(burgers_problems, [1./10., 1./15.])] + \
        [lambda p=p: discretize_stationary_from_disk(parameter_file=p)
         for p in (resource_filename('pymortests', 'testdata/parameter_stationary.ini'),)] + \
        [lambda p=p: discretize_instationary_from_disk(parameter_file=p)
         for p in (resource_filename('pymortests', 'testdata/parameter_instationary.ini'),)]


non_picklable_discretization_generators = \
        [lambda p=p, d=d: discretize_stationary_cg(p, diameter=d)[0]
         for p, d in product(non_picklable_thermalblock_problems, [1./20., 1./30.])]


discretization_generators = picklable_discretizaion_generators + non_picklable_discretization_generators