def check_general_stride(self, xp):
x = _stride_array(xp.arange(8, dtype=self.dtype), (3, 3), (-1, 2), 3)
# [[3., 5., 7.], [2., 4., 6.], [1., 3., 5.]]
v = Variable(x)
y = as_strided(v, (3, 3), (1, 2), 0)
# [[0., 2., 4.], [1., 3., 5.,], [2., 4., 6.]]
y_expected = _stride_array(xp.arange(8, dtype=self.dtype),
(3, 3), (1, 2), 0)
assert (y.array == y_expected).all()
def check_general_stride(self, xp):
x = _stride_array(xp.arange(8, dtype=self.dtype), (3, 3), (-1, 2), 3)
# [[3., 5., 7.], [2., 4., 6.], [1., 3., 5.]]
v = chainer.Variable(x)
y = F.as_strided(v, (3, 3), (1, 2), 0)
# [[0., 2., 4.], [1., 3., 5.,], [2., 4., 6.]]
y_expected = _stride_array(xp.arange(8, dtype=self.dtype), (3, 3),
(1, 2), 0)
assert (y.array == y_expected).all()
def check_general_stride_backward(self, xp):
x = _stride_array(xp.arange(8, dtype=self.dtype), (3, 3), (-1, 2), 3)
# [[3., 5., 7.], [2., 4., 6.], [1., 3., 5.]]
v = chainer.Variable(x)
y = F.as_strided(v, (3, 3), (1, 2), 0)
# [[0., 2., 4.], [1., 3., 5.,], [2., 4., 6.]]
y.grad = xp.ones(y.shape, dtype=self.dtype)
with self.assertRaises(TypeError):
gx, = chainer.grad((y, ), (v, ))
def check_general_stride_backward(self, xp):
x = _stride_array(xp.arange(8, dtype=self.dtype), (3, 3), (-1, 2), 3)
# [[3., 5., 7.], [2., 4., 6.], [1., 3., 5.]]
v = Variable(x)
y = as_strided(v, (3, 3), (1, 2), 0)
# [[0., 2., 4.], [1., 3., 5.,], [2., 4., 6.]]
y.grad = xp.ones(y.shape, dtype=self.dtype)
with self.assertRaises(TypeError):
gx, = grad((y,), (v,))
def check_general_stride(self, xp):
x = xp.arange(8, dtype=self.dtype)
y = _stride_array(x, (3, 3), (-1, 2), 3)
y_expected = xp.array(
[[3, 5, 7],
[2, 4, 6],
[1, 3, 5]],
dtype=self.dtype
)
testing.assert_allclose(y, y_expected)
def check_general_stride_backward(self, xp):
x = _stride_array(xp.arange(8, dtype=self.dtype), (3, 3), (-1, 2), 3)
# [[3., 5., 7.], [2., 4., 6.], [1., 3., 5.]]
v = chainer.Variable(x)
y = F.as_strided(v, (3, 3), (1, 2), 0)
# [[0., 2., 4.], [1., 3., 5.,], [2., 4., 6.]]
y.grad = xp.ones(y.shape, dtype=self.dtype)
gx, = chainer.grad((y, ), (v, ))
testing.assert_allclose(
gx.array,
xp.array([[0.5, 0.5, 0.], [2., 2., 1.], [1., 0.5, 0.5]],
dtype=self.dtype))
def check_general_stride_backward(self, xp):
x = _stride_array(xp.arange(8, dtype=self.dtype), (3, 3), (-1, 2), 3)
# [[3., 5., 7.], [2., 4., 6.], [1., 3., 5.]]
v = Variable(x)
y = as_strided(v, (3, 3), (1, 2), 0)
# [[0., 2., 4.], [1., 3., 5.,], [2., 4., 6.]]
y.grad = xp.ones(y.shape, dtype=self.dtype)
gx, = grad((y,), (v,))
testing.assert_allclose(gx.array,
xp.array([
[0.5, 0.5, 0.],
[2., 2., 1.],
[1., 0.5, 0.5]
], dtype=self.dtype)
)
def check_invalid_negative_index(self, xp):
x = xp.arange(8, dtype=self.dtype)
with self.assertRaises(ValueError):
_stride_array(x, (3, 3), (-1, 2), 1)
def check_unstride(self, xp):
x = xp.arange(12, dtype=self.dtype).reshape((3, 4))[::-1]
y = _stride_array(x, (12, ), (1, ), 0)
y_expected = xp.arange(12, dtype=self.dtype)
testing.assert_allclose(y, y_expected)
def check_broadcast(self, xp):
x = xp.arange(12, dtype=self.dtype).reshape((3, 4)).copy()
# [[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11]]
y = _stride_array(x, (2, 3, 4), (0, 4, 1), 0)
y_expected = _broadcast_to(xp, x, (2, 3, 4))
testing.assert_allclose(y, y_expected)
def check_flip(self, xp):
x = xp.arange(4, dtype=self.dtype)
y = _stride_array(x, (4, ), (-1, ), 3) # [3, 2, 1, 0]
y_expected = x[::-1]
testing.assert_allclose(y, y_expected)
def check_invalid_negative_index(self, xp):
x = xp.arange(8, dtype=self.dtype)
with self.assertRaises(ValueError):
_stride_array(x, (3, 3), (-1, 2), 1)
def check_unstride(self, xp):
x = xp.arange(12, dtype=self.dtype).reshape((3, 4))[::-1]
y = _stride_array(x, (12,), (1,), 0)
y_expected = xp.arange(12, dtype=self.dtype)
testing.assert_allclose(y, y_expected)
def check_broadcast(self, xp):
x = xp.arange(12, dtype=self.dtype).reshape((3, 4)).copy()
# [[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11]]
y = _stride_array(x, (2, 3, 4), (0, 4, 1), 0)
y_expected = _broadcast_to(xp, x, (2, 3, 4))
testing.assert_allclose(y, y_expected)
def check_flip(self, xp):
x = xp.arange(4, dtype=self.dtype)
y = _stride_array(x, (4,), (-1,), 3) # [3, 2, 1, 0]
y_expected = x[::-1]
testing.assert_allclose(y, y_expected)