def update(self,
feature_column,
feature_type,
num_values_quantiles_combiner,
weight_column=None):
"""Update the partial common statistics using the input value."""
# All the values in this column is null and we cannot deduce the type of
# the feature. This is not an error as this feature might have some values
# in other batches.
if feature_type is None:
return
if self.type is None:
self.type = feature_type
elif self.type != feature_type:
raise TypeError('Cannot determine the type of feature %s. '
'Found values of types %s and %s.' %
(feature_column.name, self.type, feature_type))
# np.max / np.min below cannot handle empty arrays. And there's nothing
# we can collect in this case.
if not feature_column:
return
if weight_column and (feature_column.data.num_chunks !=
weight_column.data.num_chunks):
raise ValueError(
'Expected the feature column {} and weight column {} to have the '
'same number of chunks.'.format(feature_column.name,
weight_column.name))
weight_chunks = weight_column.data.iterchunks(
) if weight_column else []
for feature_array, weight_array in six.moves.zip_longest(
feature_column.data.iterchunks(), weight_chunks,
fillvalue=None):
num_values = arrow_util.ListLengthsFromListArray(
feature_array).to_numpy()
none_mask = arrow_util.GetArrayNullBitmapAsByteArray(
feature_array).to_numpy().view(np.bool)
num_values_not_none = num_values[~none_mask]
self.num_non_missing += len(
feature_array) - feature_array.null_count
self.max_num_values = max(np.max(num_values_not_none),
self.max_num_values)
self.min_num_values = min(np.min(num_values_not_none),
self.min_num_values)
self.total_num_values += np.sum(num_values_not_none)
self.num_values_summary = num_values_quantiles_combiner.add_input(
self.num_values_summary, [num_values_not_none])
if weight_array:
weights = (arrow_util.FlattenListArray(
weight_array).to_numpy().astype(np.float32, copy=False))
if weights.size != num_values.size:
raise ValueError('Weight feature must not be missing.')
self.weighted_total_num_values += np.sum(num_values * weights)
self.weighted_num_non_missing += np.sum(weights[~none_mask])
def test_get_array_null_bitmap_as_byte_array(self):
array = pa.array([], type=pa.int32())
null_masks = arrow_util.GetArrayNullBitmapAsByteArray(array)
self.assertTrue(null_masks.equals(pa.array([], type=pa.uint8())))
array = pa.array([1, 2, None, 3, None], type=pa.int32())
null_masks = arrow_util.GetArrayNullBitmapAsByteArray(array)
self.assertTrue(
null_masks.equals(pa.array([0, 0, 1, 0, 1], type=pa.uint8())))
array = pa.array([1, 2, 3])
null_masks = arrow_util.GetArrayNullBitmapAsByteArray(array)
self.assertTrue(null_masks.equals(pa.array([0, 0, 0], type=pa.uint8())))
array = pa.array([None, None, None], type=pa.int32())
null_masks = arrow_util.GetArrayNullBitmapAsByteArray(array)
self.assertTrue(null_masks.equals(pa.array([1, 1, 1], type=pa.uint8())))
# Demonstrate that the returned array can be converted to a numpy boolean
# array w/o copying
np.testing.assert_equal(
np.array([True, True, True]), null_masks.to_numpy().view(np.bool))
def update(self,
feature_path: types.FeaturePath,
feature_array: pa.Array,
feature_type: types.FeatureNameStatisticsType,
num_values_quantiles_combiner: Any,
weights: Optional[np.ndarray] = None) -> None:
"""Update the partial common statistics using the input value."""
# All the values in this column is null and we cannot deduce the type of
# the feature. This is not an error as this feature might have some values
# in other batches.
if feature_type is None:
return
if self.type is None:
self.type = feature_type
elif self.type != feature_type:
raise TypeError('Cannot determine the type of feature %s. '
'Found values of types %s and %s.' %
(feature_path, self.type, feature_type))
# np.max / np.min below cannot handle empty arrays. And there's nothing
# we can collect in this case.
if not feature_array:
return
num_values = arrow_util.primitive_array_to_numpy(
arrow_util.ListLengthsFromListArray(feature_array))
none_mask = arrow_util.primitive_array_to_numpy(
arrow_util.GetArrayNullBitmapAsByteArray(feature_array)).view(
np.bool)
self.num_non_missing += len(feature_array) - feature_array.null_count
num_values_not_none = num_values[~none_mask]
# We do this check to avoid failing in np.min/max with empty array.
if num_values_not_none.size == 0:
return
# Use np.maximum.reduce(num_values_not_none, initial=self.max_num_values)
# once we upgrade to numpy 1.16
self.max_num_values = max(np.max(num_values_not_none),
self.max_num_values)
self.min_num_values = min(np.min(num_values_not_none),
self.min_num_values)
self.total_num_values += np.sum(num_values_not_none)
self.num_values_summary = num_values_quantiles_combiner.add_input(
self.num_values_summary, [num_values_not_none])
if weights is not None:
if weights.size != num_values.size:
raise ValueError('Weight feature must not be missing.')
self.weighted_total_num_values += np.sum(num_values * weights)
self.weighted_num_non_missing += np.sum(weights[~none_mask])
