def test_simulate_evoked():
    """ Test simulation of evoked data """

    raw = Raw(raw_fname)
    fwd = read_forward_solution(fwd_fname, force_fixed=True)
    fwd = pick_types_forward(fwd, meg=True, eeg=True, exclude=raw.info['bads'])
    cov = read_cov(cov_fname)

    evoked_template = read_evokeds(ave_fname, condition=0, baseline=None)
    evoked_template.pick_types(meg=True, eeg=True, exclude=raw.info['bads'])

    snr = 6  # dB
    tmin = -0.1
    sfreq = 1000.  # Hz
    tstep = 1. / sfreq
    n_samples = 600
    times = np.linspace(tmin, tmin + n_samples * tstep, n_samples)

    # Generate times series for 2 dipoles
    stc = simulate_sparse_stc(fwd['src'], n_dipoles=2, times=times)
    stc._data *= 1e-9

    # Generate noisy evoked data
    iir_filter = [1, -0.9]
    evoked = simulate_evoked(fwd, stc, evoked_template.info, cov, snr,
                             tmin=0.0, tmax=0.2, iir_filter=iir_filter)
    assert_array_almost_equal(evoked.times, stc.times)
    assert_true(len(evoked.data) == len(fwd['sol']['data']))

    # make a vertex that doesn't exist in fwd, should throw error
    stc_bad = stc.copy()
    mv = np.max(fwd['src'][0]['vertno'][fwd['src'][0]['inuse']])
    stc_bad.vertices[0][0] = mv + 1

    assert_raises(RuntimeError, simulate_evoked, fwd, stc_bad,
                  evoked_template.info, cov, snr, tmin=0.0, tmax=0.2)
    evoked_1 = simulate_evoked(fwd, stc, evoked_template.info, cov, np.inf,
                               tmin=0.0, tmax=0.2)
    evoked_2 = simulate_evoked(fwd, stc, evoked_template.info, cov, np.inf,
                               tmin=0.0, tmax=0.2)
    assert_array_equal(evoked_1.data, evoked_2.data)

    # test snr definition in dB
    evoked_noise = simulate_evoked(fwd, stc, evoked_template.info, cov,
                                   snr=snr, tmin=None, tmax=None,
                                   iir_filter=None)
    evoked_clean = simulate_evoked(fwd, stc, evoked_template.info, cov,
                                   snr=np.inf, tmin=None, tmax=None,
                                   iir_filter=None)
    noise = evoked_noise.data - evoked_clean.data

    empirical_snr = 10 * np.log10(np.mean((evoked_clean.data ** 2).ravel()) /
                                  np.mean((noise ** 2).ravel()))

    assert_almost_equal(snr, empirical_snr, decimal=5)

    cov['names'] = cov.ch_names[:-2]  # Error channels are different.
    assert_raises(ValueError, simulate_evoked, fwd, stc, evoked_template.info,
                  cov, snr=3., tmin=None, tmax=None, iir_filter=None)

def test_simulate_evoked():
    """Test simulation of evoked data."""

    raw = read_raw_fif(raw_fname)
    fwd = read_forward_solution(fwd_fname)
    fwd = convert_forward_solution(fwd, force_fixed=True, use_cps=False)
    fwd = pick_types_forward(fwd, meg=True, eeg=True, exclude=raw.info['bads'])
    cov = read_cov(cov_fname)

    evoked_template = read_evokeds(ave_fname, condition=0, baseline=None)
    evoked_template.pick_types(meg=True, eeg=True, exclude=raw.info['bads'])

    cov = regularize(cov, evoked_template.info)
    nave = evoked_template.nave

    tmin = -0.1
    sfreq = 1000.  # Hz
    tstep = 1. / sfreq
    n_samples = 600
    times = np.linspace(tmin, tmin + n_samples * tstep, n_samples)

    # Generate times series for 2 dipoles
    stc = simulate_sparse_stc(fwd['src'], n_dipoles=2, times=times,
                              random_state=42)

    # Generate noisy evoked data
    iir_filter = [1, -0.9]
    evoked = simulate_evoked(fwd, stc, evoked_template.info, cov,
                             iir_filter=iir_filter, nave=nave)
    assert_array_almost_equal(evoked.times, stc.times)
    assert_true(len(evoked.data) == len(fwd['sol']['data']))
    assert_equal(evoked.nave, nave)

    # make a vertex that doesn't exist in fwd, should throw error
    stc_bad = stc.copy()
    mv = np.max(fwd['src'][0]['vertno'][fwd['src'][0]['inuse']])
    stc_bad.vertices[0][0] = mv + 1

    assert_raises(RuntimeError, simulate_evoked, fwd, stc_bad,
                  evoked_template.info, cov)
    evoked_1 = simulate_evoked(fwd, stc, evoked_template.info, cov,
                               nave=np.inf)
    evoked_2 = simulate_evoked(fwd, stc, evoked_template.info, cov,
                               nave=np.inf)
    assert_array_equal(evoked_1.data, evoked_2.data)

    # Test the equivalence snr to nave
    with warnings.catch_warnings(record=True):  # deprecation
        evoked = simulate_evoked(fwd, stc, evoked_template.info, cov,
                                 snr=6, random_state=42)
    assert_allclose(np.linalg.norm(evoked.data, ord='fro'),
                    0.00078346820226502716)

    cov['names'] = cov.ch_names[:-2]  # Error channels are different.
    assert_raises(ValueError, simulate_evoked, fwd, stc, evoked_template.info,
                  cov, nave=nave, iir_filter=None)

def test_simulate_evoked():
    """Test simulation of evoked data."""
    raw = read_raw_fif(raw_fname)
    fwd = read_forward_solution(fwd_fname)
    fwd = convert_forward_solution(fwd, force_fixed=True, use_cps=False)
    fwd = pick_types_forward(fwd, meg=True, eeg=True, exclude=raw.info['bads'])
    cov = read_cov(cov_fname)

    evoked_template = read_evokeds(ave_fname, condition=0, baseline=None)
    evoked_template.pick_types(meg=True, eeg=True, exclude=raw.info['bads'])

    cov = regularize(cov, evoked_template.info)
    nave = evoked_template.nave

    tmin = -0.1
    sfreq = 1000.  # Hz
    tstep = 1. / sfreq
    n_samples = 600
    times = np.linspace(tmin, tmin + n_samples * tstep, n_samples)

    # Generate times series for 2 dipoles
    stc = simulate_sparse_stc(fwd['src'], n_dipoles=2, times=times,
                              random_state=42)

    # Generate noisy evoked data
    iir_filter = [1, -0.9]
    evoked = simulate_evoked(fwd, stc, evoked_template.info, cov,
                             iir_filter=iir_filter, nave=nave)
    assert_array_almost_equal(evoked.times, stc.times)
    assert len(evoked.data) == len(fwd['sol']['data'])
    assert_equal(evoked.nave, nave)
    assert len(evoked.info['projs']) == len(cov['projs'])
    evoked_white = whiten_evoked(evoked, cov)
    assert abs(evoked_white.data[:, 0].std() - 1.) < 0.1

    # make a vertex that doesn't exist in fwd, should throw error
    stc_bad = stc.copy()
    mv = np.max(fwd['src'][0]['vertno'][fwd['src'][0]['inuse']])
    stc_bad.vertices[0][0] = mv + 1

    pytest.raises(RuntimeError, simulate_evoked, fwd, stc_bad,
                  evoked_template.info, cov)
    evoked_1 = simulate_evoked(fwd, stc, evoked_template.info, cov,
                               nave=np.inf)
    evoked_2 = simulate_evoked(fwd, stc, evoked_template.info, cov,
                               nave=np.inf)
    assert_array_equal(evoked_1.data, evoked_2.data)

    cov['names'] = cov.ch_names[:-2]  # Error channels are different.
    with pytest.raises(RuntimeError, match='Not all channels present'):
        simulate_evoked(fwd, stc, evoked_template.info, cov)

def test_simulate_evoked():
    """ Test simulation of evoked data """

    raw = Raw(raw_fname)
    fwd = read_forward_solution(fwd_fname, force_fixed=True)
    fwd = pick_types_forward(fwd, meg=True, eeg=True, exclude=raw.info['bads'])
    cov = read_cov(cov_fname)

    evoked_template = read_evokeds(ave_fname, condition=0, baseline=None)
    evoked_template.pick_types(meg=True, eeg=True, exclude=raw.info['bads'])

    snr = 6  # dB
    tmin = -0.1
    sfreq = 1000.  # Hz
    tstep = 1. / sfreq
    n_samples = 600
    times = np.linspace(tmin, tmin + n_samples * tstep, n_samples)

    # Generate times series for 2 dipoles
    stc = simulate_sparse_stc(fwd['src'], n_dipoles=2, times=times)
    stc._data *= 1e-9

    # Generate noisy evoked data
    iir_filter = [1, -0.9]
    evoked = simulate_evoked(fwd, stc, evoked_template.info, cov, snr,
                             tmin=0.0, tmax=0.2, iir_filter=iir_filter)
    assert_array_almost_equal(evoked.times, stc.times)
    assert_true(len(evoked.data) == len(fwd['sol']['data']))

    # make a vertex that doesn't exist in fwd, should throw error
    stc_bad = stc.copy()
    mv = np.max(fwd['src'][0]['vertno'][fwd['src'][0]['inuse']])
    stc_bad.vertices[0][0] = mv + 1
    assert_raises(RuntimeError, simulate_evoked, fwd, stc_bad,
                  evoked_template.info, cov, snr, tmin=0.0, tmax=0.2)
    evoked_1 = simulate_evoked(fwd, stc, evoked_template.info, cov, np.inf,
                               tmin=0.0, tmax=0.2)
    evoked_2 = simulate_evoked(fwd, stc, evoked_template.info, cov, np.inf,
                               tmin=0.0, tmax=0.2)
    assert_array_equal(evoked_1.data, evoked_2.data)

def test_accuracy():
    """Test dipole fitting to sub-mm accuracy."""
    evoked = read_evokeds(fname_evo)[0].crop(0., 0.,)
    evoked.pick_types(meg=True, eeg=False)
    evoked.pick_channels([c for c in evoked.ch_names[::4]])
    for rad, perc_90 in zip((0.09, None), (0.002, 0.004)):
        bem = make_sphere_model('auto', rad, evoked.info,
                                relative_radii=(0.999, 0.998, 0.997, 0.995))
        src = read_source_spaces(fname_src)

        fwd = make_forward_solution(evoked.info, None, src, bem)
        fwd = convert_forward_solution(fwd, force_fixed=True, use_cps=True)
        vertices = [src[0]['vertno'], src[1]['vertno']]
        n_vertices = sum(len(v) for v in vertices)
        amp = 10e-9
        data = np.eye(n_vertices + 1)[:n_vertices]
        data[-1, -1] = 1.
        data *= amp
        stc = SourceEstimate(data, vertices, 0., 1e-3, 'sample')
        evoked.info.normalize_proj()
        sim = simulate_evoked(fwd, stc, evoked.info, cov=None, nave=np.inf)

        cov = make_ad_hoc_cov(evoked.info)
        dip = fit_dipole(sim, cov, bem, min_dist=0.001)[0]

        ds = []
        for vi in range(n_vertices):
            if vi < len(vertices[0]):
                hi = 0
                vertno = vi
            else:
                hi = 1
                vertno = vi - len(vertices[0])
            vertno = src[hi]['vertno'][vertno]
            rr = src[hi]['rr'][vertno]
            d = np.sqrt(np.sum((rr - dip.pos[vi]) ** 2))
            ds.append(d)
        # make sure that our median is sub-mm and the large majority are very
        # close (we expect some to be off by a bit e.g. because they are
        # radial)
        assert_true((np.percentile(ds, [50, 90]) < [0.0005, perc_90]).all())

# Generate source time courses from 2 dipoles and the correspond evoked data

times = np.arange(300, dtype=np.float) / raw.info['sfreq'] - 0.1
rng = np.random.RandomState(42)


def data_fun(times):
    """Function to generate random source time courses"""
    return (1e-9 * np.sin(30. * times) *
            np.exp(- (times - 0.15 + 0.05 * rng.randn(1)) ** 2 / 0.01))

stc = simulate_sparse_stc(fwd['src'], n_dipoles=2, times=times,
                          random_state=42, labels=labels, data_fun=data_fun)

###############################################################################
# Generate noisy evoked data
picks = mne.pick_types(raw.info, meg=True, exclude='bads')
iir_filter = fit_iir_model_raw(raw, order=5, picks=picks, tmin=60, tmax=180)[1]
snr = 6.  # dB
evoked = simulate_evoked(fwd, stc, info, cov, snr, iir_filter=iir_filter)

###############################################################################
# Plot
plot_sparse_source_estimates(fwd['src'], stc, bgcolor=(1, 1, 1),
                             opacity=0.5, high_resolution=True)

plt.figure()
plt.psd(evoked.data[0])

evoked.plot()

def test_make_forward_dipole():
    """Test forward-projecting dipoles."""
    rng = np.random.RandomState(0)

    evoked = read_evokeds(fname_evo)[0]
    cov = read_cov(fname_cov)
    cov['projs'] = []  # avoid proj warning
    dip_c = read_dipole(fname_dip)

    # Only use magnetometers for speed!
    picks = pick_types(evoked.info, meg='mag', eeg=False)[::8]
    evoked.pick_channels([evoked.ch_names[p] for p in picks])
    evoked.info.normalize_proj()
    info = evoked.info

    # Make new Dipole object with n_test_dipoles picked from the dipoles
    # in the test dataset.
    n_test_dipoles = 3  # minimum 3 needed to get uneven sampling in time
    dipsel = np.sort(rng.permutation(np.arange(len(dip_c)))[:n_test_dipoles])
    dip_test = Dipole(times=dip_c.times[dipsel],
                      pos=dip_c.pos[dipsel],
                      amplitude=dip_c.amplitude[dipsel],
                      ori=dip_c.ori[dipsel],
                      gof=dip_c.gof[dipsel])

    sphere = make_sphere_model(head_radius=0.1)

    # Warning emitted due to uneven sampling in time
    with pytest.warns(RuntimeWarning, match='unevenly spaced'):
        fwd, stc = make_forward_dipole(dip_test, sphere, info,
                                       trans=fname_trans)

    # stc is list of VolSourceEstimate's
    assert isinstance(stc, list)
    for n_dip in range(n_test_dipoles):
        assert isinstance(stc[n_dip], VolSourceEstimate)

    # Now simulate evoked responses for each of the test dipoles,
    # and fit dipoles to them (sphere model, MEG and EEG)
    times, pos, amplitude, ori, gof = [], [], [], [], []
    nave = 200  # add a tiny amount of noise to the simulated evokeds
    for s in stc:
        evo_test = simulate_evoked(fwd, s, info, cov,
                                   nave=nave, random_state=rng)
        # evo_test.add_proj(make_eeg_average_ref_proj(evo_test.info))
        dfit, resid = fit_dipole(evo_test, cov, sphere, None)
        times += dfit.times.tolist()
        pos += dfit.pos.tolist()
        amplitude += dfit.amplitude.tolist()
        ori += dfit.ori.tolist()
        gof += dfit.gof.tolist()

    # Create a new Dipole object with the dipole fits
    dip_fit = Dipole(times, pos, amplitude, ori, gof)

    # check that true (test) dipoles and fits are "close"
    # cf. mne/tests/test_dipole.py
    diff = dip_test.pos - dip_fit.pos
    corr = np.corrcoef(dip_test.pos.ravel(), dip_fit.pos.ravel())[0, 1]
    dist = np.sqrt(np.mean(np.sum(diff * diff, axis=1)))
    gc_dist = 180 / np.pi * \
        np.mean(np.arccos(np.sum(dip_test.ori * dip_fit.ori, axis=1)))
    amp_err = np.sqrt(np.mean((dip_test.amplitude - dip_fit.amplitude) ** 2))

    # Make sure each coordinate is close to reference
    # NB tolerance should be set relative to snr of simulated evoked!
    assert_allclose(dip_fit.pos, dip_test.pos, rtol=0, atol=1e-2,
                    err_msg='position mismatch')
    assert dist < 1e-2  # within 1 cm
    assert corr > 0.985
    assert gc_dist < 20  # less than 20 degrees
    assert amp_err < 10e-9  # within 10 nAm

    # Make sure rejection works with BEM: one dipole at z=1m
    # NB _make_forward.py:_prepare_for_forward will raise a RuntimeError
    # if no points are left after min_dist exclusions, hence 2 dips here!
    dip_outside = Dipole(times=[0., 0.001],
                         pos=[[0., 0., 1.0], [0., 0., 0.040]],
                         amplitude=[100e-9, 100e-9],
                         ori=[[1., 0., 0.], [1., 0., 0.]], gof=1)
    pytest.raises(ValueError, make_forward_dipole, dip_outside, fname_bem,
                  info, fname_trans)
    # if we get this far, can safely assume the code works with BEMs too
    # -> use sphere again below for speed

    # Now make an evenly sampled set of dipoles, some simultaneous,
    # should return a VolSourceEstimate regardless
    times = [0., 0., 0., 0.001, 0.001, 0.002]
    pos = np.random.rand(6, 3) * 0.020 + \
        np.array([0., 0., 0.040])[np.newaxis, :]
    amplitude = np.random.rand(6) * 100e-9
    ori = np.eye(6, 3) + np.eye(6, 3, -3)
    gof = np.arange(len(times)) / len(times)  # arbitrary

    dip_even_samp = Dipole(times, pos, amplitude, ori, gof)

    fwd, stc = make_forward_dipole(dip_even_samp, sphere, info,
                                   trans=fname_trans)
    assert isinstance(stc, VolSourceEstimate)
    assert_allclose(stc.times, np.arange(0., 0.003, 0.001))

def test_dipole_fitting():
    """Test dipole fitting."""
    amp = 10e-9
    tempdir = _TempDir()
    rng = np.random.RandomState(0)
    fname_dtemp = op.join(tempdir, 'test.dip')
    fname_sim = op.join(tempdir, 'test-ave.fif')
    fwd = convert_forward_solution(read_forward_solution(fname_fwd),
                                   surf_ori=False, force_fixed=True)
    evoked = read_evokeds(fname_evo)[0]
    cov = read_cov(fname_cov)
    n_per_hemi = 5
    vertices = [np.sort(rng.permutation(s['vertno'])[:n_per_hemi])
                for s in fwd['src']]
    nv = sum(len(v) for v in vertices)
    stc = SourceEstimate(amp * np.eye(nv), vertices, 0, 0.001)
    evoked = simulate_evoked(fwd, stc, evoked.info, cov, snr=20,
                             random_state=rng)
    # For speed, let's use a subset of channels (strange but works)
    picks = np.sort(np.concatenate([
        pick_types(evoked.info, meg=True, eeg=False)[::2],
        pick_types(evoked.info, meg=False, eeg=True)[::2]]))
    evoked.pick_channels([evoked.ch_names[p] for p in picks])
    evoked.add_proj(make_eeg_average_ref_proj(evoked.info))
    write_evokeds(fname_sim, evoked)

    # Run MNE-C version
    run_subprocess([
        'mne_dipole_fit', '--meas', fname_sim, '--meg', '--eeg',
        '--noise', fname_cov, '--dip', fname_dtemp,
        '--mri', fname_fwd, '--reg', '0', '--tmin', '0',
    ])
    dip_c = read_dipole(fname_dtemp)

    # Run mne-python version
    sphere = make_sphere_model(head_radius=0.1)
    dip, residuals = fit_dipole(evoked, fname_cov, sphere, fname_fwd)

    # Sanity check: do our residuals have less power than orig data?
    data_rms = np.sqrt(np.sum(evoked.data ** 2, axis=0))
    resi_rms = np.sqrt(np.sum(residuals ** 2, axis=0))
    factor = 1.
    # XXX weird, inexplicable differenc for 3.5 build we'll assume is due to
    # Anaconda bug for now...
    if os.getenv('TRAVIS', 'false') == 'true' and \
            sys.version[:3] in ('3.5', '2.7'):
        factor = 0.8
    assert_true((data_rms > factor * resi_rms).all(),
                msg='%s (factor: %s)' % ((data_rms / resi_rms).min(), factor))

    # Compare to original points
    transform_surface_to(fwd['src'][0], 'head', fwd['mri_head_t'])
    transform_surface_to(fwd['src'][1], 'head', fwd['mri_head_t'])
    src_rr = np.concatenate([s['rr'][v] for s, v in zip(fwd['src'], vertices)],
                            axis=0)
    src_nn = np.concatenate([s['nn'][v] for s, v in zip(fwd['src'], vertices)],
                            axis=0)

    # MNE-C skips the last "time" point :(
    dip.crop(dip_c.times[0], dip_c.times[-1])
    src_rr, src_nn = src_rr[:-1], src_nn[:-1]

    # check that we did at least as well
    corrs, dists, gc_dists, amp_errs, gofs = [], [], [], [], []
    for d in (dip_c, dip):
        new = d.pos
        diffs = new - src_rr
        corrs += [np.corrcoef(src_rr.ravel(), new.ravel())[0, 1]]
        dists += [np.sqrt(np.mean(np.sum(diffs * diffs, axis=1)))]
        gc_dists += [180 / np.pi * np.mean(np.arccos(np.sum(src_nn * d.ori,
                                                     axis=1)))]
        amp_errs += [np.sqrt(np.mean((amp - d.amplitude) ** 2))]
        gofs += [np.mean(d.gof)]
    assert_true(dists[0] >= dists[1] * factor, 'dists: %s' % dists)
    assert_true(corrs[0] <= corrs[1] / factor, 'corrs: %s' % corrs)
    assert_true(gc_dists[0] >= gc_dists[1] * factor,
                'gc-dists (ori): %s' % gc_dists)
    assert_true(amp_errs[0] >= amp_errs[1] * factor,
                'amplitude errors: %s' % amp_errs)
    assert_true(gofs[0] <= gofs[1] / factor, 'gof: %s' % gofs)

kwargs = dict(subjects_dir=subjects_dir, hemi='split', smoothing_steps=4,
              time_unit='s', initial_time=0.05, size=1200,
              views=['lat', 'med'])
clim = dict(kind='value', pos_lims=[1e-9, 1e-8, 1e-7])
figs = [mlab.figure(1), mlab.figure(2), mlab.figure(3), mlab.figure(4)]
brain_gen = stc_gen.plot(clim=clim, figure=figs, **kwargs)

###############################################################################
# Simulate sensor-space signals
# -----------------------------
#
# Use the forward solution and add Gaussian noise to simulate sensor-space
# (evoked) data from the known source-space signals. The amount of noise is
# controlled by `nave` (higher values imply less noise).
#
evoked_gen = simulate_evoked(fwd, stc_gen, evoked.info, cov, nave,
                             random_state=seed)

# Map the simulated sensor-space data to source-space using the inverse
# operator.
stc_inv = apply_inverse(evoked_gen, inv_op, lambda2, method=method)

###############################################################################
# Plot the point-spread of corrupted signal
# -----------------------------------------
#
# Notice that after applying the forward- and inverse-operators to the known
# point sources that the point sources have spread across the source-space.
# This spread is due to the minimum norm solution so that the signal leaks to
# nearby vertices with similar orientations so that signal ends up crossing the
# sulci and gyri.
figs = [mlab.figure(5), mlab.figure(6), mlab.figure(7), mlab.figure(8)]

times = np.arange(300, dtype=np.float) / raw.info['sfreq'] - 0.1
rng = np.random.RandomState(42)


def data_fun(times):
    """Function to generate random source time courses"""
    return (50e-9 * np.sin(30. * times) *
            np.exp(- (times - 0.15 + 0.05 * rng.randn(1)) ** 2 / 0.01))


stc = simulate_sparse_stc(fwd['src'], n_dipoles=2, times=times,
                          random_state=42, labels=labels, data_fun=data_fun)

###############################################################################
# Generate noisy evoked data
picks = mne.pick_types(raw.info, meg=True, exclude='bads')
iir_filter = fit_iir_model_raw(raw, order=5, picks=picks, tmin=60, tmax=180)[1]
nave = 100  # simulate average of 100 epochs
evoked = simulate_evoked(fwd, stc, info, cov, nave=nave, use_cps=True,
                         iir_filter=iir_filter)

###############################################################################
# Plot
plot_sparse_source_estimates(fwd['src'], stc, bgcolor=(1, 1, 1),
                             opacity=0.5, high_resolution=True)

plt.figure()
plt.psd(evoked.data[0])

evoked.plot(time_unit='s')

evoked = mne.read_evokeds(fname_ave, condition='Right Auditory',
                          baseline=(None, 0))
evoked.pick_types(meg=True, eeg=False)
evoked.crop(0.07, 0.08)

# Fit a dipole
dip = mne.fit_dipole(evoked, fname_cov, fname_bem, fname_trans)[0]

# Plot the result in 3D brain
dip.plot_locations(fname_trans, 'sample', subjects_dir)

###############################################################################
# Calculate and visualise magnetic field predicted by dipole with maximum GOF
# and compare to the measured data, highlighting the ipsilateral (right) source
fwd, stc = make_forward_dipole(dip, fname_bem, evoked.info, fname_trans)
pred_evoked = simulate_evoked(fwd, stc, evoked.info, None, snr=np.inf)

# find time point with highes GOF to plot
best_time = dip.times[np.argmax(dip.gof)]
# rememeber to create a subplot for the colorbar
fig, axes = plt.subplots(nrows=1, ncols=4, figsize=[10., 3.4])
vmin, vmax = -400, 400  # make sure each plot has same colour range

# first plot the topography at the time of the best fitting (single) dipole
plot_params = dict(times=best_time, ch_type='mag', outlines='skirt',
                   colorbar=False)
evoked.plot_topomap(time_format='Measured field', axes=axes[0], **plot_params)

# compare this to the predicted field
pred_evoked.plot_topomap(time_format='Predicted field', axes=axes[1],
                         **plot_params)

                          baseline=(None, 0))
evoked.pick_types(meg=True, eeg=False)
evoked_full = evoked.copy()
evoked.crop(0.07, 0.08)

# Fit a dipole
dip = mne.fit_dipole(evoked, fname_cov, fname_bem, fname_trans)[0]

# Plot the result in 3D brain with the MRI image.
dip.plot_locations(fname_trans, 'sample', subjects_dir, mode='orthoview')

###############################################################################
# Calculate and visualise magnetic field predicted by dipole with maximum GOF
# and compare to the measured data, highlighting the ipsilateral (right) source
fwd, stc = make_forward_dipole(dip, fname_bem, evoked.info, fname_trans)
pred_evoked = simulate_evoked(fwd, stc, evoked.info, cov=None, nave=np.inf)

# find time point with highest GOF to plot
best_idx = np.argmax(dip.gof)
best_time = dip.times[best_idx]
print('Highest GOF %0.1f%% at t=%0.1f ms with confidence volume %0.1f cm^3'
      % (dip.gof[best_idx], best_time * 1000,
         dip.conf['vol'][best_idx] * 100 ** 3))
# rememeber to create a subplot for the colorbar
fig, axes = plt.subplots(nrows=1, ncols=4, figsize=[10., 3.4])
vmin, vmax = -400, 400  # make sure each plot has same colour range

# first plot the topography at the time of the best fitting (single) dipole
plot_params = dict(times=best_time, ch_type='mag', outlines='skirt',
                   colorbar=False, time_unit='s')
evoked.plot_topomap(time_format='Measured field', axes=axes[0], **plot_params)

def test_lcmv_vector():
    """Test vector LCMV solutions."""
    info = mne.io.read_raw_fif(fname_raw).info
    # For speed and for rank-deficiency calculation simplicity,
    # just use grads:
    info = mne.pick_info(info, mne.pick_types(info, meg='grad', exclude=()))
    info.update(bads=[], projs=[])
    forward = mne.read_forward_solution(fname_fwd)
    forward = mne.pick_channels_forward(forward, info['ch_names'])
    vertices = [s['vertno'][::100] for s in forward['src']]
    n_vertices = sum(len(v) for v in vertices)
    assert 5 < n_vertices < 20
    amplitude = 100e-9
    stc = mne.SourceEstimate(amplitude * np.eye(n_vertices), vertices,
                             0, 1. / info['sfreq'])
    forward_sim = mne.convert_forward_solution(forward, force_fixed=True,
                                               use_cps=True, copy=True)
    forward_sim = mne.forward.restrict_forward_to_stc(forward_sim, stc)
    noise_cov = mne.make_ad_hoc_cov(info)
    noise_cov.update(data=np.diag(noise_cov['data']), diag=False)
    evoked = simulate_evoked(forward_sim, stc, info, noise_cov, nave=1)
    source_nn = forward_sim['source_nn']
    source_rr = forward_sim['source_rr']
    # Figure out our indices
    mask = np.concatenate([np.in1d(s['vertno'], v)
                           for s, v in zip(forward['src'], vertices)])
    mapping = np.where(mask)[0]
    assert_array_equal(source_rr, forward['source_rr'][mapping])
    # Don't check NN because we didn't rotate to surf ori
    del forward_sim

    #
    # Let's do minimum norm as a sanity check (dipole_fit is slower)
    #
    inv = make_inverse_operator(info, forward, noise_cov, loose=1.)
    stc_vector_mne = apply_inverse(evoked, inv, pick_ori='vector')
    mne_ori = stc_vector_mne.data[mapping, :, np.arange(n_vertices)]
    mne_ori /= np.linalg.norm(mne_ori, axis=-1)[:, np.newaxis]
    mne_angles = np.rad2deg(np.arccos(np.sum(mne_ori * source_nn, axis=-1)))
    assert np.mean(mne_angles) < 35

    #
    # Now let's do LCMV
    #
    data_cov = mne.make_ad_hoc_cov(info)  # just a stub for later
    with pytest.raises(ValueError, match='pick_ori must be one of'):
        make_lcmv(info, forward, data_cov, 0.05, noise_cov, pick_ori='bad')
    lcmv_ori = list()
    for ti in range(n_vertices):
        this_evoked = evoked.copy().crop(evoked.times[ti], evoked.times[ti])
        data_cov['data'] = (np.outer(this_evoked.data, this_evoked.data) +
                            noise_cov['data'])
        vals = linalg.svdvals(data_cov['data'])
        assert vals[0] / vals[-1] < 1e5  # not rank deficient
        filters = make_lcmv(info, forward, data_cov, 0.05, noise_cov)
        filters_vector = make_lcmv(info, forward, data_cov, 0.05, noise_cov,
                                   pick_ori='vector')
        stc = apply_lcmv(this_evoked, filters)
        assert isinstance(stc, mne.SourceEstimate)
        stc_vector = apply_lcmv(this_evoked, filters_vector)
        assert isinstance(stc_vector, mne.VectorSourceEstimate)
        assert_allclose(stc.data, stc_vector.magnitude().data)
        # Check the orientation by pooling across some neighbors, as LCMV can
        # have some "holes" at the points of interest
        idx = np.where(cdist(forward['source_rr'], source_rr[[ti]]) < 0.02)[0]
        lcmv_ori.append(np.mean(stc_vector.data[idx, :, 0], axis=0))
        lcmv_ori[-1] /= np.linalg.norm(lcmv_ori[-1])

    lcmv_angles = np.rad2deg(np.arccos(np.sum(lcmv_ori * source_nn, axis=-1)))
    assert np.mean(lcmv_angles) < 55

kwargs = dict(subjects_dir=subjects_dir, hemi='split', smoothing_steps=4,
              time_unit='s', initial_time=0.05, size=1200,
              views=['lat', 'med'])
clim = dict(kind='value', pos_lims=[1e-9, 1e-8, 1e-7])
figs = [mlab.figure(1), mlab.figure(2), mlab.figure(3), mlab.figure(4)]
brain_gen = stc_gen.plot(clim=clim, figure=figs, **kwargs)

###############################################################################
# Simulate sensor-space signals
# -----------------------------
#
# Use the forward solution and add Gaussian noise to simulate sensor-space
# (evoked) data from the known source-space signals. The amount of noise is
# controlled by `evoked_snr` (higher values imply less noise).
#
evoked_gen = simulate_evoked(fwd, stc_gen, evoked.info, cov, evoked_snr,
                             tmin=0., tmax=1., random_state=seed)

# Map the simulated sensor-space data to source-space using the inverse
# operator.
stc_inv = apply_inverse(evoked_gen, inv_op, lambda2, method=method)

###############################################################################
# Plot the point-spread of corrupted signal
# -----------------------------------------
#
# Notice that after applying the forward- and inverse-operators to the known
# point sources that the point sources have spread across the source-space.
# This spread is due to the minimum norm solution so that the signal leaks to
# nearby vertices with similar orientations so that signal ends up crossing the
# sulci and gyri.
figs = [mlab.figure(5), mlab.figure(6), mlab.figure(7), mlab.figure(8)]

def test_dipole_fitting():
    """Test dipole fitting."""
    amp = 100e-9
    tempdir = _TempDir()
    rng = np.random.RandomState(0)
    fname_dtemp = op.join(tempdir, 'test.dip')
    fname_sim = op.join(tempdir, 'test-ave.fif')
    fwd = convert_forward_solution(read_forward_solution(fname_fwd),
                                   surf_ori=False, force_fixed=True,
                                   use_cps=True)
    evoked = read_evokeds(fname_evo)[0]
    cov = read_cov(fname_cov)
    n_per_hemi = 5
    vertices = [np.sort(rng.permutation(s['vertno'])[:n_per_hemi])
                for s in fwd['src']]
    nv = sum(len(v) for v in vertices)
    stc = SourceEstimate(amp * np.eye(nv), vertices, 0, 0.001)
    evoked = simulate_evoked(fwd, stc, evoked.info, cov, nave=evoked.nave,
                             random_state=rng)
    # For speed, let's use a subset of channels (strange but works)
    picks = np.sort(np.concatenate([
        pick_types(evoked.info, meg=True, eeg=False)[::2],
        pick_types(evoked.info, meg=False, eeg=True)[::2]]))
    evoked.pick_channels([evoked.ch_names[p] for p in picks])
    evoked.add_proj(make_eeg_average_ref_proj(evoked.info))
    write_evokeds(fname_sim, evoked)

    # Run MNE-C version
    run_subprocess([
        'mne_dipole_fit', '--meas', fname_sim, '--meg', '--eeg',
        '--noise', fname_cov, '--dip', fname_dtemp,
        '--mri', fname_fwd, '--reg', '0', '--tmin', '0',
    ])
    dip_c = read_dipole(fname_dtemp)

    # Run mne-python version
    sphere = make_sphere_model(head_radius=0.1)
    with warnings.catch_warnings(record=True):
        dip, residuals = fit_dipole(evoked, cov, sphere, fname_fwd)

    # Sanity check: do our residuals have less power than orig data?
    data_rms = np.sqrt(np.sum(evoked.data ** 2, axis=0))
    resi_rms = np.sqrt(np.sum(residuals ** 2, axis=0))
    assert_true((data_rms > resi_rms * 0.95).all(),
                msg='%s (factor: %s)' % ((data_rms / resi_rms).min(), 0.95))

    # Compare to original points
    transform_surface_to(fwd['src'][0], 'head', fwd['mri_head_t'])
    transform_surface_to(fwd['src'][1], 'head', fwd['mri_head_t'])
    assert_equal(fwd['src'][0]['coord_frame'], FIFF.FIFFV_COORD_HEAD)
    src_rr = np.concatenate([s['rr'][v] for s, v in zip(fwd['src'], vertices)],
                            axis=0)
    src_nn = np.concatenate([s['nn'][v] for s, v in zip(fwd['src'], vertices)],
                            axis=0)

    # MNE-C skips the last "time" point :(
    out = dip.crop(dip_c.times[0], dip_c.times[-1])
    assert_true(dip is out)
    src_rr, src_nn = src_rr[:-1], src_nn[:-1]

    # check that we did about as well
    corrs, dists, gc_dists, amp_errs, gofs = [], [], [], [], []
    for d in (dip_c, dip):
        new = d.pos
        diffs = new - src_rr
        corrs += [np.corrcoef(src_rr.ravel(), new.ravel())[0, 1]]
        dists += [np.sqrt(np.mean(np.sum(diffs * diffs, axis=1)))]
        gc_dists += [180 / np.pi * np.mean(np.arccos(np.sum(src_nn * d.ori,
                                                     axis=1)))]
        amp_errs += [np.sqrt(np.mean((amp - d.amplitude) ** 2))]
        gofs += [np.mean(d.gof)]
    factor = 0.8
    assert_true(dists[0] / factor >= dists[1], 'dists: %s' % dists)
    assert_true(corrs[0] * factor <= corrs[1], 'corrs: %s' % corrs)
    assert_true(gc_dists[0] / factor >= gc_dists[1] * 0.8,
                'gc-dists (ori): %s' % gc_dists)
    assert_true(amp_errs[0] / factor >= amp_errs[1],
                'amplitude errors: %s' % amp_errs)
    # This one is weird because our cov/sim/picking is weird
    assert_true(gofs[0] * factor <= gofs[1] * 2, 'gof: %s' % gofs)

def test_dipole_fitting():
    """Test dipole fitting"""
    amp = 10e-9
    tempdir = _TempDir()
    rng = np.random.RandomState(0)
    fname_dtemp = op.join(tempdir, "test.dip")
    fname_sim = op.join(tempdir, "test-ave.fif")
    fwd = convert_forward_solution(read_forward_solution(fname_fwd), surf_ori=False, force_fixed=True)
    evoked = read_evokeds(fname_evo)[0]
    cov = read_cov(fname_cov)
    n_per_hemi = 5
    vertices = [np.sort(rng.permutation(s["vertno"])[:n_per_hemi]) for s in fwd["src"]]
    nv = sum(len(v) for v in vertices)
    stc = SourceEstimate(amp * np.eye(nv), vertices, 0, 0.001)
    evoked = simulate_evoked(fwd, stc, evoked.info, cov, snr=20, random_state=rng)
    # For speed, let's use a subset of channels (strange but works)
    picks = np.sort(
        np.concatenate(
            [pick_types(evoked.info, meg=True, eeg=False)[::2], pick_types(evoked.info, meg=False, eeg=True)[::2]]
        )
    )
    evoked.pick_channels([evoked.ch_names[p] for p in picks])
    evoked.add_proj(make_eeg_average_ref_proj(evoked.info))
    write_evokeds(fname_sim, evoked)

    # Run MNE-C version
    run_subprocess(
        [
            "mne_dipole_fit",
            "--meas",
            fname_sim,
            "--meg",
            "--eeg",
            "--noise",
            fname_cov,
            "--dip",
            fname_dtemp,
            "--mri",
            fname_fwd,
            "--reg",
            "0",
            "--tmin",
            "0",
        ]
    )
    dip_c = read_dipole(fname_dtemp)

    # Run mne-python version
    sphere = make_sphere_model(head_radius=0.1)
    dip, residuals = fit_dipole(evoked, fname_cov, sphere, fname_fwd)

    # Sanity check: do our residuals have less power than orig data?
    data_rms = np.sqrt(np.sum(evoked.data ** 2, axis=0))
    resi_rms = np.sqrt(np.sum(residuals ** 2, axis=0))
    assert_true((data_rms > resi_rms).all())

    # Compare to original points
    transform_surface_to(fwd["src"][0], "head", fwd["mri_head_t"])
    transform_surface_to(fwd["src"][1], "head", fwd["mri_head_t"])
    src_rr = np.concatenate([s["rr"][v] for s, v in zip(fwd["src"], vertices)], axis=0)
    src_nn = np.concatenate([s["nn"][v] for s, v in zip(fwd["src"], vertices)], axis=0)

    # MNE-C skips the last "time" point :(
    dip.crop(dip_c.times[0], dip_c.times[-1])
    src_rr, src_nn = src_rr[:-1], src_nn[:-1]

    # check that we did at least as well
    corrs, dists, gc_dists, amp_errs, gofs = [], [], [], [], []
    for d in (dip_c, dip):
        new = d.pos
        diffs = new - src_rr
        corrs += [np.corrcoef(src_rr.ravel(), new.ravel())[0, 1]]
        dists += [np.sqrt(np.mean(np.sum(diffs * diffs, axis=1)))]
        gc_dists += [180 / np.pi * np.mean(np.arccos(np.sum(src_nn * d.ori, axis=1)))]
        amp_errs += [np.sqrt(np.mean((amp - d.amplitude) ** 2))]
        gofs += [np.mean(d.gof)]
    assert_true(dists[0] >= dists[1], "dists: %s" % dists)
    assert_true(corrs[0] <= corrs[1], "corrs: %s" % corrs)
    assert_true(gc_dists[0] >= gc_dists[1], "gc-dists (ori): %s" % gc_dists)
    assert_true(amp_errs[0] >= amp_errs[1], "amplitude errors: %s" % amp_errs)
    assert_true(gofs[0] <= gofs[1], "gof: %s" % gofs)