def test_internal_overlap_slices():
# Slicing an array never generates internal overlap
x = np.zeros([17,34,71,97], dtype=np.int16)
rng = np.random.RandomState(1234)
def random_slice(n, step):
start = rng.randint(0, n+1, dtype=np.intp)
stop = rng.randint(start, n+1, dtype=np.intp)
if rng.randint(0, 2, dtype=np.intp) == 0:
stop, start = start, stop
step *= -1
return slice(start, stop, step)
cases = 0
min_count = 5000
while cases < min_count:
steps = tuple(rng.randint(1, 11, dtype=np.intp)
if rng.randint(0, 5, dtype=np.intp) == 0 else 1
for j in range(x.ndim))
t1 = np.arange(x.ndim)
rng.shuffle(t1)
s1 = tuple(random_slice(p, s) for p, s in zip(x.shape, steps))
a = x[s1].transpose(t1)
assert_(not internal_overlap(a))
cases += 1
def check_internal_overlap(a, manual_expected=None):
got = internal_overlap(a)
# Brute-force check
m = set()
ranges = tuple(xrange(n) for n in a.shape)
for v in itertools.product(*ranges):
offset = sum(s*w for s, w in zip(a.strides, v))
if offset in m:
expected = True
break
else:
m.add(offset)
else:
expected = False
# Compare
if got != expected:
assert_equal(got, expected, err_msg=repr((a.strides, a.shape)))
if manual_expected is not None and expected != manual_expected:
assert_equal(expected, manual_expected)
return got
def check_internal_overlap(a, manual_expected=None):
got = internal_overlap(a)
# Brute-force check
m = set()
ranges = tuple(xrange(n) for n in a.shape)
for v in itertools.product(*ranges):
offset = sum(s*w for s, w in zip(a.strides, v))
if offset in m:
expected = True
break
else:
m.add(offset)
else:
expected = False
# Compare
if got != expected:
assert_equal(got, expected, err_msg=repr((a.strides, a.shape)))
if manual_expected is not None and expected != manual_expected:
assert_equal(expected, manual_expected)
return got