def unique1d(values):
"""
Hash table-based unique
"""
if np.issubdtype(values.dtype, np.floating):
table = htable.Float64HashTable(len(values))
uniques = np.array(table.unique(_ensure_float64(values)),
dtype=np.float64)
elif np.issubdtype(values.dtype, np.datetime64):
table = htable.Int64HashTable(len(values))
uniques = table.unique(_ensure_int64(values))
uniques = uniques.view('M8[ns]')
elif np.issubdtype(values.dtype, np.timedelta64):
table = htable.Int64HashTable(len(values))
uniques = table.unique(_ensure_int64(values))
uniques = uniques.view('m8[ns]')
elif np.issubdtype(values.dtype, np.signedinteger):
table = htable.Int64HashTable(len(values))
uniques = table.unique(_ensure_int64(values))
elif np.issubdtype(values.dtype, np.unsignedinteger):
table = htable.UInt64HashTable(len(values))
uniques = table.unique(_ensure_uint64(values))
else:
# its cheaper to use a String Hash Table than Object
if lib.infer_dtype(values) in ['string']:
table = htable.StringHashTable(len(values))
else:
table = htable.PyObjectHashTable(len(values))
uniques = table.unique(_ensure_object(values))
return uniques
def test_get_labels_groupby_for_Int64(writable):
table = ht.Int64HashTable()
vals = np.array([1, 2, -1, 2, 1, -1], dtype=np.int64)
vals.flags.writeable = writable
arr, unique = table.get_labels_groupby(vals)
expected_arr = np.array([0, 1, -1, 1, 0, -1], dtype=np.intp)
expected_unique = np.array([1, 2], dtype=np.int64)
tm.assert_numpy_array_equal(arr, expected_arr)
tm.assert_numpy_array_equal(unique, expected_unique)
def __init__(self, comp_ids, ngroups, levels, labels):
self.levels = levels
self.labels = labels
self.comp_ids = comp_ids.astype(np.int64)
self.k = len(labels)
self.tables = [hashtable.Int64HashTable(ngroups) for _ in range(self.k)]
self._populate_tables()
def get_flattened_list(
comp_ids: np.ndarray,
ngroups: int,
levels: Iterable[Index],
labels: Iterable[np.ndarray],
) -> List[Tuple]:
"""Map compressed group id -> key tuple."""
comp_ids = comp_ids.astype(np.int64, copy=False)
arrays: DefaultDict[int, List[int]] = defaultdict(list)
for labs, level in zip(labels, levels):
table = hashtable.Int64HashTable(ngroups)
table.map(comp_ids, labs.astype(np.int64, copy=False))
for i in range(ngroups):
arrays[i].append(level[table.get_item(i)])
return [tuple(array) for array in arrays.values()]
def compress_group_index(group_index, sort: bool = True):
"""
Group_index is offsets into cartesian product of all possible labels. This
space can be huge, so this function compresses it, by computing offsets
(comp_ids) into the list of unique labels (obs_group_ids).
"""
size_hint = len(group_index)
table = hashtable.Int64HashTable(size_hint)
group_index = ensure_int64(group_index)
# note, group labels come out ascending (ie, 1,2,3 etc)
comp_ids, obs_group_ids = table.get_labels_groupby(group_index)
if sort and len(obs_group_ids) > 0:
obs_group_ids, comp_ids = _reorder_by_uniques(obs_group_ids, comp_ids)
return ensure_int64(comp_ids), ensure_int64(obs_group_ids)
