def test_n_iter_without_progress():
# Use a dummy negative n_iter_without_progress and check output on stdout
random_state = check_random_state(0)
X = random_state.randn(100, 10)
for method in ["barnes_hut", "exact"]:
tsne = TSNE(n_iter_without_progress=-1,
verbose=2,
learning_rate=1e8,
random_state=0,
method=method,
n_iter=351,
init="random")
tsne._N_ITER_CHECK = 1
tsne._EXPLORATION_N_ITER = 0
old_stdout = sys.stdout
sys.stdout = StringIO()
try:
tsne.fit_transform(X)
finally:
out = sys.stdout.getvalue()
sys.stdout.close()
sys.stdout = old_stdout
# The output needs to contain the value of n_iter_without_progress
assert ("did not make any progress during the "
"last -1 episodes. Finished." in out)
def test_bh_match_exact():
# check that the ``barnes_hut`` method match the exact one when
# ``angle = 0`` and ``perplexity > n_samples / 3``
random_state = check_random_state(0)
n_features = 10
X = random_state.randn(30, n_features).astype(np.float32)
X_embeddeds = {}
n_iter = {}
for method in ['exact', 'barnes_hut']:
tsne = TSNE(n_components=2,
method=method,
learning_rate=1.0,
init="random",
random_state=0,
n_iter=251,
perplexity=30.0,
angle=0)
# Kill the early_exaggeration
tsne._EXPLORATION_N_ITER = 0
X_embeddeds[method] = tsne.fit_transform(X)
n_iter[method] = tsne.n_iter_
assert n_iter['exact'] == n_iter['barnes_hut']
assert_allclose(X_embeddeds['exact'], X_embeddeds['barnes_hut'], rtol=1e-4)