[074d3d]: / mne / stats / tests / test_cluster_level.py

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# Authors: The MNE-Python contributors.
# License: BSD-3-Clause
# Copyright the MNE-Python contributors.
import os
from functools import partial
import numpy as np
import pytest
from numpy.testing import (
assert_allclose,
assert_array_almost_equal,
assert_array_equal,
assert_equal,
)
from scipy import linalg, sparse, stats
from mne import MixedSourceEstimate, SourceEstimate, SourceSpaces, VolSourceEstimate
from mne.fixes import _eye_array
from mne.stats import combine_adjacency, ttest_ind_no_p
from mne.stats.cluster_level import (
f_oneway,
permutation_cluster_1samp_test,
permutation_cluster_test,
spatio_temporal_cluster_1samp_test,
spatio_temporal_cluster_test,
summarize_clusters_stc,
ttest_1samp_no_p,
)
from mne.utils import _record_warnings, catch_logging
n_space = 50
def _get_conditions():
noise_level = 20
n_time_1 = 20
n_time_2 = 13
normfactor = np.hanning(20).sum()
rng = np.random.RandomState(42)
condition1_1d = rng.randn(n_time_1, n_space) * noise_level
for c in condition1_1d:
c[:] = np.convolve(c, np.hanning(20), mode="same") / normfactor
condition2_1d = rng.randn(n_time_2, n_space) * noise_level
for c in condition2_1d:
c[:] = np.convolve(c, np.hanning(20), mode="same") / normfactor
pseudoekp = 10 * np.hanning(25)[None, :]
condition1_1d[:, 25:] += pseudoekp
condition2_1d[:, 25:] -= pseudoekp
condition1_2d = condition1_1d[:, :, np.newaxis]
condition2_2d = condition2_1d[:, :, np.newaxis]
return condition1_1d, condition2_1d, condition1_2d, condition2_2d
def test_thresholds(numba_conditional):
"""Test automatic threshold calculations."""
# within subjects
rng = np.random.RandomState(0)
X = rng.randn(10, 1, 1) + 0.08
want_thresh = -stats.t.ppf(0.025, len(X) - 1)
assert 0.03 < stats.ttest_1samp(X[:, 0, 0], 0)[1] < 0.05
my_fun = partial(ttest_1samp_no_p)
with catch_logging() as log:
with pytest.warns(RuntimeWarning, match="threshold is only valid"):
out = permutation_cluster_1samp_test(
X, stat_fun=my_fun, seed=0, verbose=True, out_type="mask"
)
log = log.getvalue()
assert str(want_thresh)[:6] in log
assert len(out[1]) == 1 # 1 cluster
assert_allclose(out[2], 0.033203, atol=1e-6)
# between subjects
Y = rng.randn(10, 1, 1)
Z = rng.randn(10, 1, 1) - 0.7
X = [X, Y, Z]
want_thresh = stats.f.ppf(1.0 - 0.05, 2, sum(len(a) for a in X) - len(X))
p = stats.f_oneway(*X)[1]
assert 0.03 < p < 0.05
my_fun = partial(f_oneway) # just to make the check fail
with catch_logging() as log:
with pytest.warns(RuntimeWarning, match="threshold is only valid"):
out = permutation_cluster_test(
X, tail=1, stat_fun=my_fun, seed=0, verbose=True, out_type="mask"
)
log = log.getvalue()
assert str(want_thresh)[:6] in log
assert len(out[1]) == 1 # 1 cluster
assert_allclose(out[2], 0.041992, atol=1e-6)
with pytest.warns(RuntimeWarning, match='Ignoring argument "tail"'):
permutation_cluster_test(X, tail=0, out_type="mask")
# nan handling in TFCE
X = np.repeat(X[0], 2, axis=1)
X[:, 1] = 0
with (
_record_warnings(),
pytest.warns(RuntimeWarning, match="invalid value"),
): # NumPy
out = permutation_cluster_1samp_test(
X, seed=0, threshold=dict(start=0, step=0.1), out_type="mask"
)
assert (out[2] < 0.05).any()
assert not (out[2] < 0.05).all()
X[:, 0] = 0
with pytest.raises(RuntimeError, match="finite"):
with np.errstate(invalid="ignore"):
permutation_cluster_1samp_test(
X,
seed=0,
threshold=dict(start=0, step=0.1),
buffer_size=None,
out_type="mask",
)
def test_cache_dir(tmp_path, numba_conditional):
"""Test use of cache dir."""
tempdir = str(tmp_path)
orig_dir = os.getenv("MNE_CACHE_DIR", None)
orig_size = os.getenv("MNE_MEMMAP_MIN_SIZE", None)
rng = np.random.RandomState(0)
X = rng.randn(9, 2, 10)
try:
os.environ["MNE_MEMMAP_MIN_SIZE"] = "1K"
os.environ["MNE_CACHE_DIR"] = tempdir
# Fix error for #1507: in-place when memmapping
with catch_logging() as log_file:
permutation_cluster_1samp_test(
X,
buffer_size=None,
n_jobs=2,
n_permutations=1,
seed=0,
stat_fun=ttest_1samp_no_p,
verbose=False,
out_type="mask",
)
assert "independently" not in log_file.getvalue()
# ensure that non-independence yields warning
stat_fun = partial(ttest_1samp_no_p, sigma=1e-3)
random_state = np.random.default_rng(0)
with _record_warnings(), pytest.warns(RuntimeWarning, match="independently"):
permutation_cluster_1samp_test(
X,
buffer_size=10,
n_jobs=2,
n_permutations=1,
seed=random_state,
stat_fun=stat_fun,
verbose=False,
out_type="mask",
)
finally:
if orig_dir is not None:
os.environ["MNE_CACHE_DIR"] = orig_dir
else:
del os.environ["MNE_CACHE_DIR"]
if orig_size is not None:
os.environ["MNE_MEMMAP_MIN_SIZE"] = orig_size
else:
del os.environ["MNE_MEMMAP_MIN_SIZE"]
def test_permutation_large_n_samples(numba_conditional):
"""Test that non-replacement works with large N."""
X = np.random.RandomState(0).randn(72, 1) + 1
for n_samples in (11, 72):
tails = (0, 1) if n_samples <= 20 else (0,)
for tail in tails:
H0 = permutation_cluster_1samp_test(
X[:n_samples], threshold=1e-4, tail=tail, out_type="mask"
)[-1]
assert H0.shape == (1024,)
assert len(np.unique(H0)) >= 1024 - (H0 == 0).sum()
def test_permutation_step_down_p(numba_conditional):
"""Test cluster level permutations with step_down_p."""
rng = np.random.RandomState(0)
# subjects, time points, spatial points
X = rng.randn(9, 2, 10)
# add some significant points
X[:, 0:2, 0:2] += 2 # span two time points and two spatial points
X[:, 1, 5:9] += 0.5 # span four time points with 4x smaller amplitude
thresh = 2
# make sure it works when we use ALL points in step-down
t, clusters, p, H0 = permutation_cluster_1samp_test(
X, threshold=thresh, step_down_p=1.0, out_type="mask"
)
# make sure using step-down will actually yield improvements sometimes
t, clusters, p_old, H0 = permutation_cluster_1samp_test(
X, threshold=thresh, step_down_p=0.0, out_type="mask"
)
assert_equal(np.sum(p_old < 0.05), 1) # just spatial cluster
p_min = np.min(p_old)
assert_allclose(p_min, 0.003906, atol=1e-6)
t, clusters, p_new, H0 = permutation_cluster_1samp_test(
X, threshold=thresh, step_down_p=0.05, out_type="mask"
)
assert_equal(np.sum(p_new < 0.05), 2) # time one rescued
assert np.all(p_old >= p_new)
p_next = p_new[(p_new > 0.004) & (p_new < 0.05)][0]
assert_allclose(p_next, 0.015625, atol=1e-6)
def test_cluster_permutation_test(numba_conditional):
"""Test cluster level permutations tests."""
condition1_1d, condition2_1d, condition1_2d, condition2_2d = _get_conditions()
for condition1, condition2 in zip(
(condition1_1d, condition1_2d), (condition2_1d, condition2_2d)
):
T_obs, clusters, cluster_p_values, hist = permutation_cluster_test(
[condition1, condition2],
n_permutations=100,
tail=1,
seed=1,
buffer_size=None,
out_type="mask",
)
p_min = np.min(cluster_p_values)
assert_equal(np.sum(cluster_p_values < 0.05), 1)
assert_allclose(p_min, 0.01, atol=1e-6)
# test with 2 jobs and buffer_size enabled
buffer_size = condition1.shape[1] // 10
T_obs, clusters, cluster_p_values_buff, hist = permutation_cluster_test(
[condition1, condition2],
n_permutations=100,
tail=1,
seed=1,
n_jobs=2,
buffer_size=buffer_size,
out_type="mask",
)
assert_array_equal(cluster_p_values, cluster_p_values_buff)
def stat_fun(X, Y):
return stats.f_oneway(X, Y)[0]
with pytest.warns(RuntimeWarning, match="is only valid"):
permutation_cluster_test(
[condition1, condition2],
n_permutations=1,
stat_fun=stat_fun,
out_type="mask",
)
@pytest.mark.parametrize(
"stat_fun", [ttest_1samp_no_p, partial(ttest_1samp_no_p, sigma=1e-1)]
)
def test_cluster_permutation_t_test(numba_conditional, stat_fun):
"""Test cluster level permutations T-test."""
condition1_1d, _, condition1_2d, _ = _get_conditions()
# use a very large sigma to make sure Ts are not independent
for condition1, p in ((condition1_1d, 0.01), (condition1_2d, 0.01)):
# these are so significant we can get away with fewer perms
T_obs, clusters, cluster_p_values, hist = permutation_cluster_1samp_test(
condition1,
n_permutations=100,
tail=0,
seed=1,
out_type="mask",
buffer_size=None,
)
assert_equal(np.sum(cluster_p_values < 0.05), 1)
p_min = np.min(cluster_p_values)
assert_allclose(p_min, p, atol=1e-6)
T_obs_pos, _, cluster_p_values_pos, _ = permutation_cluster_1samp_test(
condition1,
n_permutations=100,
tail=1,
threshold=1.67,
seed=1,
stat_fun=stat_fun,
out_type="mask",
buffer_size=None,
)
T_obs_neg, _, cluster_p_values_neg, _ = permutation_cluster_1samp_test(
-condition1,
n_permutations=100,
tail=-1,
threshold=-1.67,
seed=1,
stat_fun=stat_fun,
buffer_size=None,
out_type="mask",
)
assert_array_equal(T_obs_pos, -T_obs_neg)
assert_array_equal(cluster_p_values_pos < 0.05, cluster_p_values_neg < 0.05)
# test with 2 jobs and buffer_size enabled
buffer_size = condition1.shape[1] // 10
with _record_warnings(): # sometimes "independently"
(
T_obs_neg_buff,
_,
cluster_p_values_neg_buff,
_,
) = permutation_cluster_1samp_test(
-condition1,
n_permutations=100,
tail=-1,
out_type="mask",
threshold=-1.67,
seed=1,
n_jobs=2,
stat_fun=stat_fun,
buffer_size=buffer_size,
)
assert_array_equal(T_obs_neg, T_obs_neg_buff)
assert_array_equal(cluster_p_values_neg, cluster_p_values_neg_buff)
# Bad stat_fun
with pytest.raises(TypeError, match="must be .* ndarray"):
permutation_cluster_1samp_test(
condition1, threshold=1, stat_fun=lambda x: None, out_type="mask"
)
with pytest.raises(ValueError, match="not compatible"):
permutation_cluster_1samp_test(
condition1,
threshold=1,
stat_fun=lambda x: stat_fun(x)[:-1],
out_type="mask",
)
def test_cluster_permutation_with_adjacency(numba_conditional, monkeypatch):
"""Test cluster level permutations with adjacency matrix."""
pytest.importorskip("sklearn")
from sklearn.feature_extraction.image import grid_to_graph
condition1_1d, condition2_1d, _, _ = _get_conditions()
n_pts = condition1_1d.shape[1]
# we don't care about p-values in any of these, so do fewer permutations
args = dict(
seed=None,
max_step=1,
exclude=None,
out_type="mask",
step_down_p=0,
t_power=1,
threshold=1.67,
check_disjoint=False,
n_permutations=50,
)
did_warn = False
for X1d, func, spatio_temporal_func in [
(
condition1_1d,
permutation_cluster_1samp_test,
spatio_temporal_cluster_1samp_test,
),
(
[condition1_1d, condition2_1d],
permutation_cluster_test,
spatio_temporal_cluster_test,
),
]:
out = func(X1d, **args)
adjacency = grid_to_graph(1, n_pts)
out_adjacency = func(X1d, adjacency=adjacency, **args)
assert_array_equal(out[0], out_adjacency[0])
for a, b in zip(out_adjacency[1], out[1]):
assert_array_equal(out[0][a], out[0][b])
assert np.all(a[b])
# test spatio-temporal w/o time adjacency (repeat spatial pattern)
adjacency_2 = sparse.coo_array(
linalg.block_diag(
adjacency.asfptype().todense(), adjacency.asfptype().todense()
)
)
# nesting here is time then space:
adjacency_2a = combine_adjacency(_eye_array(2), adjacency)
assert_array_equal(
adjacency_2.toarray().astype(bool), adjacency_2a.toarray().astype(bool)
)
if isinstance(X1d, list):
X1d_2 = [np.concatenate((x, x), axis=1) for x in X1d]
else:
X1d_2 = np.concatenate((X1d, X1d), axis=1)
out_adjacency_2 = func(X1d_2, adjacency=adjacency_2, **args)
# make sure we were operating on the same values
split = len(out[0])
assert_array_equal(out[0], out_adjacency_2[0][:split])
assert_array_equal(out[0], out_adjacency_2[0][split:])
# make sure we really got 2x the number of original clusters
n_clust_orig = len(out[1])
assert len(out_adjacency_2[1]) == 2 * n_clust_orig
# Make sure that we got the old ones back
data_1 = {np.sum(out[0][b[:n_pts]]) for b in out[1]}
data_2 = {np.sum(out_adjacency_2[0][a]) for a in out_adjacency_2[1][:]}
assert len(data_1.intersection(data_2)) == len(data_1)
# now use the other algorithm
if isinstance(X1d, list):
X1d_3 = [np.reshape(x, (-1, 2, n_space)) for x in X1d_2]
else:
X1d_3 = np.reshape(X1d_2, (-1, 2, n_space))
out_adjacency_3 = spatio_temporal_func(
X1d_3,
n_permutations=50,
adjacency=adjacency,
max_step=0,
threshold=1.67,
check_disjoint=True,
)
# make sure we were operating on the same values
split = len(out[0])
assert_array_equal(out[0], out_adjacency_3[0][0])
assert_array_equal(out[0], out_adjacency_3[0][1])
# make sure we really got 2x the number of original clusters
assert len(out_adjacency_3[1]) == 2 * n_clust_orig
# Make sure that we got the old ones back
data_1 = {np.sum(out[0][b[:n_pts]]) for b in out[1]}
data_2 = {np.sum(out_adjacency_3[0][a[0], a[1]]) for a in out_adjacency_3[1]}
assert len(data_1.intersection(data_2)) == len(data_1)
# test new versus old method
out_adjacency_4 = spatio_temporal_func(
X1d_3, n_permutations=50, adjacency=adjacency, max_step=2, threshold=1.67
)
out_adjacency_5 = spatio_temporal_func(
X1d_3, n_permutations=50, adjacency=adjacency, max_step=1, threshold=1.67
)
# clusters could be in a different order
sums_4 = [np.sum(out_adjacency_4[0][a]) for a in out_adjacency_4[1]]
sums_5 = [np.sum(out_adjacency_4[0][a]) for a in out_adjacency_5[1]]
sums_4 = np.sort(sums_4)
sums_5 = np.sort(sums_5)
assert_array_almost_equal(sums_4, sums_5)
monkeypatch.delenv("MNE_FORCE_SERIAL", raising=False)
with pytest.raises(ValueError, match="must not be less"):
spatio_temporal_func(
X1d_3,
n_permutations=1,
adjacency=adjacency,
max_step=1,
threshold=1.67,
n_jobs=-1000,
)
# not enough TFCE params
with pytest.raises(KeyError, match="threshold, if dict, must have"):
spatio_temporal_func(X1d_3, adjacency=adjacency, threshold=dict(me="hello"))
# too extreme a start threshold
with _record_warnings() as w:
spatio_temporal_func(
X1d_3, adjacency=adjacency, threshold=dict(start=10, step=1)
)
if not did_warn:
messages = [str(ww.message) for ww in w]
assert any("is more extreme" in message for message in messages), messages
did_warn = True
with pytest.raises(ValueError, match="threshold.*<= 0 for tail == -1"):
spatio_temporal_func(
X1d_3, adjacency=adjacency, tail=-1, threshold=dict(start=1, step=-1)
)
with pytest.warns(RuntimeWarning, match="threshold.* is more extreme"):
spatio_temporal_func(
X1d_3, adjacency=adjacency, tail=1, threshold=dict(start=100, step=1)
)
bad_con = adjacency.todense()
with pytest.raises(ValueError, match="must be a SciPy sparse matrix"):
spatio_temporal_func(
X1d_3, n_permutations=50, adjacency=bad_con, max_step=1, threshold=1.67
)
bad_con = adjacency.tocsr()[:-1, :-1].tocoo()
with pytest.raises(ValueError, match="adjacency.*the correct size"):
spatio_temporal_func(
X1d_3, n_permutations=50, adjacency=bad_con, max_step=1, threshold=1.67
)
with pytest.raises(TypeError, match="must be a"):
spatio_temporal_func(X1d_3, adjacency=adjacency, threshold=[])
with pytest.raises(ValueError, match="Invalid value for the 'tail'"):
# sometimes ignoring tail
with _record_warnings():
spatio_temporal_func(X1d_3, adjacency=adjacency, tail=2)
# make sure it actually found a significant point
out_adjacency_6 = spatio_temporal_func(
X1d_3,
n_permutations=50,
adjacency=adjacency,
max_step=1,
threshold=dict(start=1, step=1),
)
assert np.min(out_adjacency_6[2]) < 0.05
with pytest.raises(ValueError, match="not compatible"):
with _record_warnings():
spatio_temporal_func(
X1d_3,
n_permutations=50,
adjacency=adjacency,
threshold=1e-3,
stat_fun=lambda *x: f_oneway(*x)[:-1],
buffer_size=None,
)
@pytest.mark.parametrize(
"threshold",
[
0.1,
pytest.param(dict(start=0.0, step=0.5), id="TFCE"),
],
)
@pytest.mark.parametrize("kind", ("1samp", "ind"))
def test_permutation_cluster_signs(threshold, kind):
"""Test cluster signs."""
# difference between two conditions for 3 subjects x 2 vertices x 2 times
X = np.array(
[[[-10, 5], [-2, -7]], [[-4, 5], [-8, -0]], [[-6, 3], [-4, -2]]], float
)
want_signs = np.sign(np.mean(X, axis=0))
n_permutations = 1
if kind == "1samp":
func = permutation_cluster_1samp_test
stat_fun = ttest_1samp_no_p
use_X = X
else:
assert kind == "ind"
func = permutation_cluster_test
stat_fun = ttest_ind_no_p
use_X = [X, np.random.RandomState(0).randn(*X.shape) * 0.1]
tobs, clu, clu_pvalues, _ = func(
use_X,
n_permutations=n_permutations,
threshold=threshold,
tail=0,
stat_fun=stat_fun,
out_type="mask",
)
clu_signs = np.zeros(X.shape[1:])
used = np.zeros(X.shape[1:])
assert len(clu) == len(clu_pvalues)
for c, p in zip(clu, clu_pvalues):
assert not used[c].any()
assert len(np.unique(np.sign(tobs[c]))) == 1
clu_signs[c] = np.sign(tobs[c])[0]
used[c] = True
assert used.all()
assert clu_signs.all()
assert_array_equal(np.sign(tobs), want_signs)
assert_array_equal(clu_signs, want_signs)
def test_permutation_adjacency_equiv(numba_conditional):
"""Test cluster level permutations with and without adjacency."""
pytest.importorskip("sklearn")
from sklearn.feature_extraction.image import grid_to_graph
rng = np.random.RandomState(0)
# subjects, time points, spatial points
n_time = 2
n_space = 4
X = rng.randn(6, n_time, n_space)
# add some significant points
X[:, :, 0:2] += 10 # span two time points and two spatial points
X[:, 1, 3] += 20 # span one time point
max_steps = [1, 1, 1, 2, 1]
# This will run full algorithm in two ways, then the ST-algorithm in 2 ways
# All of these should give the same results
adjs = [
None,
grid_to_graph(n_time, n_space),
grid_to_graph(1, n_space),
grid_to_graph(1, n_space),
None,
]
stat_map = None
thresholds = [2, 2, 2, 2, dict(start=0.01, step=1.0)]
sig_counts = [2, 2, 2, 2, 5]
stat_fun = partial(ttest_1samp_no_p, sigma=1e-3)
cs = None
ps = None
for thresh, count, max_step, adj in zip(thresholds, sig_counts, max_steps, adjs):
t, clusters, p, H0 = permutation_cluster_1samp_test(
X,
threshold=thresh,
adjacency=adj,
n_jobs=2,
max_step=max_step,
stat_fun=stat_fun,
seed=0,
out_type="mask",
)
# make sure our output datatype is correct
assert isinstance(clusters[0], np.ndarray)
assert clusters[0].dtype == np.dtype(bool)
assert_array_equal(clusters[0].shape, X.shape[1:])
# make sure all comparisons were done; for TFCE, no perm
# should come up empty
inds = np.where(p < 0.05)[0]
assert_equal(len(inds), count)
assert_allclose(p[inds], 0.03125, atol=1e-6)
if isinstance(thresh, dict):
assert_equal(len(clusters), n_time * n_space)
assert np.all(H0 != 0)
continue
this_cs = [clusters[ii] for ii in inds]
this_ps = p[inds]
this_stat_map = np.zeros((n_time, n_space), dtype=bool)
for ci, c in enumerate(this_cs):
if isinstance(c, tuple):
this_c = np.zeros((n_time, n_space), bool)
for x, y in zip(c[0], c[1]):
this_stat_map[x, y] = True
this_c[x, y] = True
this_cs[ci] = this_c
c = this_c
this_stat_map[c] = True
if cs is None:
ps = this_ps
cs = this_cs
if stat_map is None:
stat_map = this_stat_map
assert_array_equal(ps, this_ps)
assert len(cs) == len(this_cs)
for c1, c2 in zip(cs, this_cs):
assert_array_equal(c1, c2)
assert_array_equal(stat_map, this_stat_map)
def test_spatio_temporal_cluster_adjacency(numba_conditional):
"""Test spatio-temporal cluster permutations."""
pytest.importorskip("sklearn")
from sklearn.feature_extraction.image import grid_to_graph
condition1_1d, condition2_1d, condition1_2d, condition2_2d = _get_conditions()
rng = np.random.RandomState(0)
noise1_2d = rng.randn(condition1_2d.shape[0], condition1_2d.shape[1], 10)
data1_2d = np.transpose(np.dstack((condition1_2d, noise1_2d)), [0, 2, 1])
noise2_d2 = rng.randn(condition2_2d.shape[0], condition2_2d.shape[1], 10)
data2_2d = np.transpose(np.dstack((condition2_2d, noise2_d2)), [0, 2, 1])
adj = grid_to_graph(data1_2d.shape[-1], 1)
threshold = dict(start=4.0, step=2)
T_obs, clusters, p_values_adj, hist = spatio_temporal_cluster_test(
[data1_2d, data2_2d],
adjacency=adj,
n_permutations=50,
tail=1,
seed=1,
threshold=threshold,
buffer_size=None,
)
buffer_size = data1_2d.size // 10
T_obs, clusters, p_values_no_adj, hist = spatio_temporal_cluster_test(
[data1_2d, data2_2d],
n_permutations=50,
tail=1,
seed=1,
threshold=threshold,
n_jobs=2,
buffer_size=buffer_size,
)
assert_equal(np.sum(p_values_adj < 0.05), np.sum(p_values_no_adj < 0.05))
# make sure results are the same without buffer_size
T_obs, clusters, p_values2, _ = spatio_temporal_cluster_test(
[data1_2d, data2_2d],
n_permutations=50,
tail=1,
seed=1,
threshold=threshold,
n_jobs=2,
buffer_size=None,
)
assert_array_equal(p_values_no_adj, p_values2)
pytest.raises(
ValueError,
spatio_temporal_cluster_test,
[data1_2d, data2_2d],
tail=1,
threshold=-2.0,
)
pytest.raises(
ValueError,
spatio_temporal_cluster_test,
[data1_2d, data2_2d],
tail=-1,
threshold=2.0,
)
pytest.raises(
ValueError,
spatio_temporal_cluster_test,
[data1_2d, data2_2d],
tail=0,
threshold=-1,
)
def ttest_1samp(X):
"""Return T-values."""
return stats.ttest_1samp(X, 0)[0]
@pytest.mark.parametrize("kind", ("surface", "volume", "mixed"))
def test_summarize_clusters(kind):
"""Test cluster summary stcs."""
src_surf = SourceSpaces(
[dict(vertno=np.arange(10242), type="surf") for _ in range(2)]
)
assert src_surf.kind == "surface"
src_vol = SourceSpaces([dict(vertno=np.arange(10), type="vol")])
assert src_vol.kind == "volume"
if kind == "surface":
src = src_surf
klass = SourceEstimate
elif kind == "volume":
src = src_vol
klass = VolSourceEstimate
else:
assert kind == "mixed"
src = src_surf + src_vol
klass = MixedSourceEstimate
n_vertices = sum(len(s["vertno"]) for s in src)
clu = (
np.random.random([1, n_vertices]),
[(np.array([0]), np.array([0, 2, 4]))],
np.array([0.02, 0.1]),
np.array([12, -14, 30]),
)
kwargs = dict()
if kind == "volume":
with pytest.raises(ValueError, match="did not match"):
summarize_clusters_stc(clu)
assert len(src) == 1
kwargs["vertices"] = [src[0]["vertno"]]
elif kind == "mixed":
kwargs["vertices"] = src
stc_sum = summarize_clusters_stc(clu, **kwargs)
assert isinstance(stc_sum, klass)
assert stc_sum.data.shape[1] == 2
clu[2][0] = 0.3
with pytest.raises(RuntimeError, match="No significant"):
summarize_clusters_stc(clu, **kwargs)
def test_permutation_test_H0(numba_conditional):
"""Test that H0 is populated properly during testing."""
rng = np.random.RandomState(0)
data = rng.rand(7, 10, 1) - 0.5
with pytest.warns(RuntimeWarning, match="No clusters found"):
t, clust, p, h0 = spatio_temporal_cluster_1samp_test(
data, threshold=100, n_permutations=1024, seed=rng
)
assert_equal(len(h0), 0)
for n_permutations in (1024, 65, 64, 63):
t, clust, p, h0 = spatio_temporal_cluster_1samp_test(
data, threshold=0.1, n_permutations=n_permutations, seed=rng
)
assert_equal(len(h0), min(n_permutations, 64))
assert isinstance(clust[0], tuple) # sets of indices
for tail, thresh in zip((-1, 0, 1), (-0.1, 0.1, 0.1)):
t, clust, p, h0 = spatio_temporal_cluster_1samp_test(
data, threshold=thresh, seed=rng, tail=tail, out_type="mask"
)
assert isinstance(clust[0], np.ndarray) # bool mask
# same as "128 if tail else 64"
assert_equal(len(h0), 2 ** (7 - (tail == 0))) # exact test
def test_tfce_thresholds(numba_conditional):
"""Test TFCE thresholds."""
rng = np.random.RandomState(0)
data = rng.randn(7, 10, 1) - 0.5
# if tail==-1, step must also be negative
with pytest.raises(ValueError, match="must be < 0 for tail == -1"):
permutation_cluster_1samp_test(
data, tail=-1, out_type="mask", threshold=dict(start=0, step=0.1)
)
# this works (smoke test)
permutation_cluster_1samp_test(
data, tail=-1, out_type="mask", threshold=dict(start=0, step=-0.1)
)
# thresholds must be monotonically increasing
with pytest.raises(ValueError, match="must be monotonically increasing"):
permutation_cluster_1samp_test(
data, tail=1, out_type="mask", threshold=dict(start=1, step=-0.5)
)
# Should work with 2D data too
permutation_cluster_1samp_test(X=data[..., 0], threshold=dict(start=0, step=0.2))
# 1D gives slices, 2D+ gives boolean masks
@pytest.mark.parametrize("shape", ((11,), (11, 3), (11, 1, 2)))
@pytest.mark.parametrize("out_type", ("mask", "indices"))
@pytest.mark.parametrize("adjacency", (None, "sparse"))
@pytest.mark.parametrize("threshold", (None, dict(start=0, step=0.1)))
def test_output_equiv(shape, out_type, adjacency, threshold):
"""Test equivalence of output types."""
rng = np.random.RandomState(0)
n_subjects = 10
data = rng.randn(n_subjects, *shape)
data -= data.mean(axis=0, keepdims=True)
data[:, 2:4] += 2
data[:, 6:9] += 2
tfce = isinstance(threshold, dict)
want_mask = np.zeros(shape, int)
if not tfce:
want_mask[2:4] = 1
want_mask[6:9] = 2
else:
want_mask = np.arange(want_mask.size).reshape(shape) + 1
if adjacency is not None:
assert adjacency == "sparse"
adjacency = combine_adjacency(*shape)
clusters = permutation_cluster_1samp_test(
X=data,
n_permutations=1,
adjacency=adjacency,
out_type=out_type,
threshold=threshold,
)[1]
got_mask = np.zeros_like(want_mask)
for n, clu in enumerate(clusters, 1):
if out_type == "mask":
if len(shape) == 1 and adjacency is None:
assert isinstance(clu, tuple)
assert len(clu) == 1
assert isinstance(clu[0], slice)
else:
assert isinstance(clu, np.ndarray)
assert clu.dtype == np.dtype(bool)
assert clu.shape == shape
got_mask[clu] = n
else:
assert isinstance(clu, tuple)
for c in clu:
assert isinstance(c, np.ndarray)
assert c.dtype.kind == "i"
assert out_type == "indices"
got_mask[np.ix_(*clu)] = n
assert_array_equal(got_mask, want_mask)