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-rw-r--r--numpy/lib/arraysetops.py21
-rw-r--r--numpy/lib/tests/test_arraysetops.py46
2 files changed, 66 insertions, 1 deletions
diff --git a/numpy/lib/arraysetops.py b/numpy/lib/arraysetops.py
index eb5c488e4..7600e17be 100644
--- a/numpy/lib/arraysetops.py
+++ b/numpy/lib/arraysetops.py
@@ -209,6 +209,16 @@ def unique(ar, return_index=False, return_inverse=False,
flattened subarrays are sorted in lexicographic order starting with the
first element.
+ .. versionchanged: NumPy 1.21
+ If nan values are in the input array, a single nan is put
+ to the end of the sorted unique values.
+
+ Also for complex arrays all NaN values are considered equivalent
+ (no matter whether the NaN is in the real or imaginary part).
+ As the representant for the returned array the smallest one in the
+ lexicographical order is chosen - see np.sort for how the lexicographical
+ order is defined for complex arrays.
+
Examples
--------
>>> np.unique([1, 1, 2, 2, 3, 3])
@@ -324,7 +334,16 @@ def _unique1d(ar, return_index=False, return_inverse=False,
aux = ar
mask = np.empty(aux.shape, dtype=np.bool_)
mask[:1] = True
- mask[1:] = aux[1:] != aux[:-1]
+ if aux.shape[0] > 0 and aux.dtype.kind in "cfmM" and np.isnan(aux[-1]):
+ if aux.dtype.kind == "c": # for complex all NaNs are considered equivalent
+ aux_firstnan = np.searchsorted(np.isnan(aux), True, side='left')
+ else:
+ aux_firstnan = np.searchsorted(aux, aux[-1], side='left')
+ mask[1:aux_firstnan] = (aux[1:aux_firstnan] != aux[:aux_firstnan - 1])
+ mask[aux_firstnan] = True
+ mask[aux_firstnan + 1:] = False
+ else:
+ mask[1:] = aux[1:] != aux[:-1]
ret = (aux[mask],)
if return_index:
diff --git a/numpy/lib/tests/test_arraysetops.py b/numpy/lib/tests/test_arraysetops.py
index de2ef255c..d62da9efb 100644
--- a/numpy/lib/tests/test_arraysetops.py
+++ b/numpy/lib/tests/test_arraysetops.py
@@ -564,6 +564,52 @@ class TestUnique:
assert_equal(a3_idx.dtype, np.intp)
assert_equal(a3_inv.dtype, np.intp)
+ # test for ticket 2111 - float
+ a = [2.0, np.nan, 1.0, np.nan]
+ ua = [1.0, 2.0, np.nan]
+ ua_idx = [2, 0, 1]
+ ua_inv = [1, 2, 0, 2]
+ ua_cnt = [1, 1, 2]
+ assert_equal(np.unique(a), ua)
+ assert_equal(np.unique(a, return_index=True), (ua, ua_idx))
+ assert_equal(np.unique(a, return_inverse=True), (ua, ua_inv))
+ assert_equal(np.unique(a, return_counts=True), (ua, ua_cnt))
+
+ # test for ticket 2111 - complex
+ a = [2.0-1j, np.nan, 1.0+1j, complex(0.0, np.nan), complex(1.0, np.nan)]
+ ua = [1.0+1j, 2.0-1j, complex(0.0, np.nan)]
+ ua_idx = [2, 0, 3]
+ ua_inv = [1, 2, 0, 2, 2]
+ ua_cnt = [1, 1, 3]
+ assert_equal(np.unique(a), ua)
+ assert_equal(np.unique(a, return_index=True), (ua, ua_idx))
+ assert_equal(np.unique(a, return_inverse=True), (ua, ua_inv))
+ assert_equal(np.unique(a, return_counts=True), (ua, ua_cnt))
+
+ # test for ticket 2111 - datetime64
+ nat = np.datetime64('nat')
+ a = [np.datetime64('2020-12-26'), nat, np.datetime64('2020-12-24'), nat]
+ ua = [np.datetime64('2020-12-24'), np.datetime64('2020-12-26'), nat]
+ ua_idx = [2, 0, 1]
+ ua_inv = [1, 2, 0, 2]
+ ua_cnt = [1, 1, 2]
+ assert_equal(np.unique(a), ua)
+ assert_equal(np.unique(a, return_index=True), (ua, ua_idx))
+ assert_equal(np.unique(a, return_inverse=True), (ua, ua_inv))
+ assert_equal(np.unique(a, return_counts=True), (ua, ua_cnt))
+
+ # test for ticket 2111 - timedelta
+ nat = np.timedelta64('nat')
+ a = [np.timedelta64(1, 'D'), nat, np.timedelta64(1, 'h'), nat]
+ ua = [np.timedelta64(1, 'h'), np.timedelta64(1, 'D'), nat]
+ ua_idx = [2, 0, 1]
+ ua_inv = [1, 2, 0, 2]
+ ua_cnt = [1, 1, 2]
+ assert_equal(np.unique(a), ua)
+ assert_equal(np.unique(a, return_index=True), (ua, ua_idx))
+ assert_equal(np.unique(a, return_inverse=True), (ua, ua_inv))
+ assert_equal(np.unique(a, return_counts=True), (ua, ua_cnt))
+
def test_unique_axis_errors(self):
assert_raises(TypeError, self._run_axis_tests, object)
assert_raises(TypeError, self._run_axis_tests,