def diagonal(a, offset=0, axis1=0, axis2=1): # pylint: disable=missing-docstring
a = asarray(a).data
maybe_rank = a.shape.rank
if maybe_rank is not None and offset == 0 and (
axis1 == maybe_rank - 2 or axis1 == -2) and (axis2 == maybe_rank - 1 or
axis2 == -1):
return utils.tensor_to_ndarray(tf.linalg.diag_part(a))
a = moveaxis(utils.tensor_to_ndarray(a), (axis1, axis2), (-2, -1)).data
a_shape = tf.shape(a)
def _zeros(): # pylint: disable=missing-docstring
return (tf.zeros(tf.concat([a_shape[:-1], [0]], 0), dtype=a.dtype), 0)
# All zeros since diag_part doesn't handle all possible k (aka offset).
# Written this way since cond will run shape inference on both branches,
# and diag_part shape inference will fail when offset is out of bounds.
a, offset = utils.cond(
utils.logical_or(
utils.less_equal(offset, -1 * utils.getitem(a_shape, -2)),
utils.greater_equal(offset, utils.getitem(a_shape, -1)),
), _zeros, lambda: (a, offset))
a = utils.tensor_to_ndarray(tf.linalg.diag_part(a, k=offset))
return a
def _diag_part(v, k):
v_shape = tf.shape(v)
v, k = utils.cond(
utils.logical_or(
utils.less_equal(k, -1 * utils.getitem(v_shape, 0)),
utils.greater_equal(k, utils.getitem(v_shape, 1)),
), lambda: (tf.zeros([0, 0], dtype=v.dtype), 0), lambda: (v, k))
result = tf.linalg.diag_part(v, k=k)
return result
def f(a, b): # pylint: disable=missing-docstring
# We can't assign to captured variable `axisa`, so make a new variable
axis_a = axisa
axis_b = axisb
axis_c = axisc
if axis is not None:
axis_a = axis
axis_b = axis
axis_c = axis
if axis_a < 0:
axis_a = utils.add(axis_a, tf.rank(a))
if axis_b < 0:
axis_b = utils.add(axis_b, tf.rank(b))
def maybe_move_axis_to_last(a, axis):
def move_axis_to_last(a, axis):
return tf.transpose(
a,
tf.concat([
tf.range(axis),
tf.range(axis + 1, tf.rank(a)), [axis]
],
axis=0))
return utils.cond(axis == utils.subtract(tf.rank(a), 1), lambda: a,
lambda: move_axis_to_last(a, axis))
a = maybe_move_axis_to_last(a, axis_a)
b = maybe_move_axis_to_last(b, axis_b)
a_dim = utils.getitem(tf.shape(a), -1)
b_dim = utils.getitem(tf.shape(b), -1)
def maybe_pad_0(a, size_of_last_dim):
def pad_0(a):
return tf.pad(
a,
tf.concat([
tf.zeros([tf.rank(a) - 1, 2], tf.int32),
tf.constant([[0, 1]], tf.int32)
],
axis=0))
return utils.cond(size_of_last_dim == 2, lambda: pad_0(a),
lambda: a)
a = maybe_pad_0(a, a_dim)
b = maybe_pad_0(b, b_dim)
c = tf.linalg.cross(*utils.tf_broadcast(a, b))
if axis_c < 0:
axis_c = utils.add(axis_c, tf.rank(c))
def move_last_to_axis(a, axis):
r = tf.rank(a)
return tf.transpose(
a,
tf.concat([tf.range(axis), [r - 1],
tf.range(axis, r - 1)],
axis=0))
c = utils.cond(
(a_dim == 2) & (b_dim == 2),
lambda: c[..., 2],
lambda: utils.cond( # pylint: disable=g-long-lambda
axis_c == utils.subtract(tf.rank(c), 1), lambda: c, lambda:
move_last_to_axis(c, axis_c)))
return c