def test_imputation_shape(self):
"""Verify the shapes of the imputed matrix for different strategies."""
X = np.random.randn(10, 2)
X[::2] = np.nan
for strategy in ['mean', 'median', 'most_frequent']:
imputer = Imputer(strategy=strategy)
X_imputed = imputer.fit_transform(X)
assert_equal(X_imputed.shape, (10, 2))
X_imputed = imputer.fit_transform(sparse.csr_matrix(X))
assert_equal(X_imputed.shape, (10, 2))
def calculate_all_metafeatures(X, y, categorical, dataset_name,
calculate=None, dont_calculate=None, densify_threshold=1000):
logger = get_logger(__name__)
"""Calculate all metafeatures."""
helper_functions.clear()
metafeatures.clear()
mf_ = dict()
visited = set()
to_visit = deque()
to_visit.extend(metafeatures)
X_transformed = None
y_transformed = None
# TODO calculate the numpy metafeatures after all others to consume less
# memory
while len(to_visit) > 0:
name = to_visit.pop()
if calculate is not None and name not in calculate:
continue
if dont_calculate is not None and name in dont_calculate:
continue
if name in npy_metafeatures:
if X_transformed is None:
# TODO make sure this is done as efficient as possible (no copy for
# sparse matrices because of wrong sparse format)
sparse = scipy.sparse.issparse(X)
ohe = OneHotEncoder(categorical_features=categorical, sparse=True)
X_transformed = ohe.fit_transform(X)
imputer = Imputer(strategy='mean', copy=False, dtype=X.dtype)
X_transformed = imputer.fit_transform(X_transformed)
standard_scaler = StandardScaler(copy=False)
X_transformed = standard_scaler.fit_transform(X_transformed)
# Transform the array which indicates the categorical metafeatures
number_numerical = np.sum(~np.array(categorical))
categorical_transformed = [True] * (X_transformed.shape[1] -
number_numerical) + \
[False] * number_numerical
# Densify the transformed matrix
if not sparse and scipy.sparse.issparse(X_transformed):
bytes_per_float = X_transformed.dtype.itemsize
num_elements = X_transformed.shape[0] * X_transformed.shape[1]
megabytes_required = num_elements * bytes_per_float / 1000 / 1000
if megabytes_required < densify_threshold:
X_transformed = X_transformed.todense()
# This is not only important for datasets which are somehow
# sorted in a strange way, but also prevents lda from failing in
# some cases.
# Because this is advanced indexing, a copy of the data is returned!!!
X_transformed = check_array(X_transformed,
force_all_finite=True,
accept_sparse='csr')
rs = np.random.RandomState(42)
indices = np.arange(X_transformed.shape[0])
rs.shuffle(indices)
# TODO Shuffle inplace
X_transformed = X_transformed[indices]
y_transformed = y[indices]
X_ = X_transformed
y_ = y_transformed
categorical_ = categorical_transformed
else:
X_ = X
y_ = y
categorical_ = categorical
dependency = metafeatures.get_dependency(name)
if dependency is not None:
is_metafeature = dependency in metafeatures
is_helper_function = dependency in helper_functions
if is_metafeature and is_helper_function:
raise NotImplementedError()
elif not is_metafeature and not is_helper_function:
raise ValueError(dependency)
elif is_metafeature and not metafeatures.is_calculated(dependency):
to_visit.appendleft(name)
continue
elif is_helper_function and not helper_functions.is_calculated(
dependency):
logger.info("%s: Going to calculate: %s", dataset_name,
dependency)
value = helper_functions[dependency](X_, y_, categorical_)
helper_functions.set_value(dependency, value)
mf_[dependency] = value
logger.info("%s: Going to calculate: %s", dataset_name,
name)
value = metafeatures[name](X_, y_, categorical_)
metafeatures.set_value(name, value)
mf_[name] = value
visited.add(name)
mf_ = DatasetMetafeatures(dataset_name, mf_)
return mf_
