def test_gaussian_mixture_log_probabilities():
from sklearn.mixture._gaussian_mixture import _estimate_log_gaussian_prob
# test against with _naive_lmvnpdf_diag
rng = np.random.RandomState(0)
rand_data = RandomData(rng)
n_samples = 500
n_features = rand_data.n_features
n_components = rand_data.n_components
means = rand_data.means
covars_diag = rng.rand(n_components, n_features)
X = rng.rand(n_samples, n_features)
log_prob_naive = _naive_lmvnpdf_diag(X, means, covars_diag)
# full covariances
precs_full = np.array([np.diag(1. / np.sqrt(x)) for x in covars_diag])
log_prob = _estimate_log_gaussian_prob(X, means, precs_full, 'full')
assert_array_almost_equal(log_prob, log_prob_naive)
# diag covariances
precs_chol_diag = 1. / np.sqrt(covars_diag)
log_prob = _estimate_log_gaussian_prob(X, means, precs_chol_diag, 'diag')
assert_array_almost_equal(log_prob, log_prob_naive)
# tied
covars_tied = np.array([x for x in covars_diag]).mean(axis=0)
precs_tied = np.diag(np.sqrt(1. / covars_tied))
log_prob_naive = _naive_lmvnpdf_diag(X, means,
[covars_tied] * n_components)
log_prob = _estimate_log_gaussian_prob(X, means, precs_tied, 'tied')
assert_array_almost_equal(log_prob, log_prob_naive)
# spherical
covars_spherical = covars_diag.mean(axis=1)
precs_spherical = 1. / np.sqrt(covars_diag.mean(axis=1))
log_prob_naive = _naive_lmvnpdf_diag(X, means,
[[k] * n_features for k in
covars_spherical])
log_prob = _estimate_log_gaussian_prob(X, means,
precs_spherical, 'spherical')
assert_array_almost_equal(log_prob, log_prob_naive)
def get_means_resp(X,log_resp, cov):
_, means_, covariances_ = _gm._estimate_gaussian_parameters(X, np.exp(log_resp), 1e-6, cov)
precisions_cholesky_ = _gm._compute_precision_cholesky( covariances_, cov)
log_resp = _gm._estimate_log_gaussian_prob( X, means_, precisions_cholesky_,cov)
return means_, log_resp
