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pytensor
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58586211
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58586211
authored
8月 07, 2015
作者:
Iban Harlouchet
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差异文件
numpydoc for theano/tensor/nnet/neighbours.py
上级
c0ef6069
隐藏空白字符变更
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1 个修改的文件
包含
98 行增加
和
93 行删除
+98
-93
neighbours.py
theano/tensor/nnet/neighbours.py
+98
-93
没有找到文件。
theano/tensor/nnet/neighbours.py
浏览文件 @
58586211
...
...
@@ -18,17 +18,21 @@ class Images2Neibs(Op):
def
__init__
(
self
,
mode
=
'valid'
):
"""
:type mode: str
:param mode: Possible values:
'valid': Requires an input that is a multiple of the
pooling factor (in each direction)
Parameters
----------
mode : {'valid', 'ignore_borders', 'wrap_centered'}
'valid': Requires an input that is a multiple of the
pooling factor (in each direction).
'ignore_borders': Same as valid, but will ignore the borders
if the shape(s) of the input
is not a multiple of the pooling factor(s)
if the shape(s) of the input
is not a multiple of the pooling
factor(s).
'wrap_centered' : ?? TODO comment
:return:
Returns
-------
Reshapes the input as a 2D tensor where each row is an
pooling example
pooling example.
"""
if
mode
not
in
[
'valid'
,
'wrap_centered'
,
'ignore_borders'
]:
raise
NotImplementedError
(
"Only the mode valid, ignore_borders"
...
...
@@ -46,20 +50,22 @@ class Images2Neibs(Op):
def
make_node
(
self
,
ten4
,
neib_shape
,
neib_step
=
None
):
"""
:param ten4: a list of lists of images
ten4 is of shape (list 1 dim, list 2 dim,
row, col)
:param neib_shape: (r,c) where r is the height of the neighborhood
in rows and c is the width of the neighborhood
in columns
:param neib_step: (dr,dc) where dr is the number of rows to
skip between patch and dc is the number of
columns. When None, this is the same as
neib_shape(patch are disjoint)
output:
a 2D matrix, written using the following pattern
Parameters
----------
ten4 : a list of lists of images
ten4 is of shape (list 1 dim, list 2 dim, row, col).
neib_shape
(r,c) where r is the height of the neighborhood in rows and c is
the width of the neighborhood in columns.
neib_step
(dr,dc) where dr is the number of rows to skip between patch and dc
is the number of columns. When None, this is the same as neib_shape
(patch are disjoint).
Returns
-------
matrix
A 2D matrix, written using the following pattern
idx = 0
for i in xrange(list 1 dim)
for j in xrange(list 2 dim)
...
...
@@ -68,9 +74,10 @@ class Images2Neibs(Op):
output[idx,:]
= flattened version of ten4[i,j,l:l+r,k:k+c]
idx += 1
(note: t
he op isn't necessarily implemented internally with these
.. note:: T
he op isn't necessarily implemented internally with these
for loops, they're just the easiest way to describe the output
pattern)
pattern.
"""
ten4
=
T
.
as_tensor_variable
(
ten4
)
neib_shape
=
T
.
as_tensor_variable
(
neib_shape
)
...
...
@@ -420,61 +427,45 @@ def images2neibs(ten4, neib_shape, neib_step=None, mode='valid'):
"""
Function :func:`images2neibs <theano.sandbox.neighbours.images2neibs>`
allows to apply a sliding window operation to a tensor containing
images
or other two-dimensional objects.
The sliding window operation loops
over points in input data and stores a rectangular neighbourhood of
each point.
It is possible to assign a step of selecting patches (parameter
`neib_step`).
:param ten4: A 4-dimensional tensor which represents
a list of lists of images.a list of lists of images.
It should have shape (list 1 dim, list 2 dim,
row, col). The first two dimensions can be
useful to store different channels and batches.
:type ten4: A 4d tensor-like.
:param neib_shape: A tuple containing two
values: height and width of the neighbourhood.
It should have shape (r,c) where r is the height of the
neighborhood in rows and c is the width of the neighborhood
in columns
:type neib_shape: A 1d tensor-like of 2 values.
:param neib_step: (dr,dc) where dr is the number of rows to
skip between patch and dc is the number of
columns. The parameter should be a tuple of two elements:
number
of rows and number of columns to skip each iteration.
Basically, when the step is 1, the neighbourhood of every
first element is taken and every possible rectangular
subset is returned. By default it is equal to
`neib_shape` in other words, the
patches are disjoint. When the step is greater than
`neib_shape`, some elements are omitted. When None, this
is the same as
neib_shape(patch are disjoint)
.. note:: Currently the step size should be chosen in the way that the
corresponding dimension :math:`i` (width or height) is equal to
:math:`n * step
\
_size_i + neib
\
_shape_i` for some :math:`n`
:type neib_step: A 1d tensor-like of 2 values.
:param mode:
Possible values:
images or other two-dimensional objects.
The sliding window operation loops over points in input data and stores
a rectangular neighbourhood of each point.
It is possible to assign a step of selecting patches (parameter `neib_step`).
Parameters
----------
ten4 : A 4d tensor-like
A 4-dimensional tensor which represents a list of lists of images.
It should have shape (list 1 dim, list 2 dim, row, col). The first
two dimensions can be useful to store different channels and batches.
neib_shape : A 1d tensor-like of 2 values
A tuple containing two values: height and width of the neighbourhood.
It should have shape (r,c) where r is the height of the neighborhood
in rows and c is the width of the neighborhood in columns.
neib_step : A 1d tensor-like of 2 values
(dr,dc) where dr is the number of rows to skip between patch and dc is
the number of columns. The parameter should be a tuple of two elements:
number of rows and number of columns to skip each iteration.
Basically, when the step is 1, the neighbourhood of every first element
is taken and every possible rectangular subset is returned.
By default it is equal to `neib_shape` in other words, the patches are
disjoint. When the step is greater than `neib_shape`, some elements are
omitted. When None, this is the same as neib_shape (patch are disjoint).
.. note:: Currently the step size should be chosen in the way that the
corresponding dimension :math:`i` (width or height) is equal to
:math:`n * step
\
_size_i + neib
\
_shape_i` for some :math:`n`
mode : {'valid', 'ignore_borders', 'wrap_centered}
``valid``
Requires an input that is a multiple of the
pooling factor (in each direction)
pooling factor (in each direction).
``ignore_borders``
Same as valid, but will ignore the borders
if the shape(s) of the input
is not a multiple of the pooling factor(s)
Same as valid, but will ignore the borders if the shape(s) of
the input is not a multiple of the pooling factor(s).
``wrap_centered``
?? TODO comment
:type mode: str
:return:
Returns
-------
Reshapes the input as a 2D tensor where each row is an
pooling example. Pseudo-code of the output:
...
...
@@ -493,7 +484,8 @@ def images2neibs(ten4, neib_shape, neib_step=None, mode='valid'):
these for loops, they're just the easiest way to describe the
output pattern.
Example:
Examples
--------
.. code-block:: python
...
...
@@ -512,6 +504,7 @@ def images2neibs(ten4, neib_shape, neib_step=None, mode='valid'):
.. note:: The underlying code will construct a 2D tensor of disjoint
patches 5x5. The output has shape 4x25.
"""
return
Images2Neibs
(
mode
)(
ten4
,
neib_shape
,
neib_step
)
...
...
@@ -524,25 +517,36 @@ def neibs2images(neibs, neib_shape, original_shape, mode='valid'):
the output of :func:`images2neibs <theano.sandbox.neigbours.neibs2images>`
and reconstructs its input.
:param neibs: matrix like the one obtained by
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`
:param neib_shape: `neib_shape` that was used in
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`
:param original_shape: original shape of the 4d tensor given to
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`
:return: Reconstructs the input of
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`,
a 4d tensor of shape `original_shape`.
.. note:: Currently, the function doesn't support tensors created with
`neib_step` different from default value. This means that it may be
impossible to compute the gradient of a variable gained by
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>` w.r.t.
its inputs in this case, because it uses
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>` for
gradient computation.
Parameters
----------
neibs: matrix
Like the one obtained by
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`.
neib_shape
`neib_shape` that was used in
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`.
original_shape
Original shape of the 4d tensor given to
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`
Returns
-------
Reconstructs the input of
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`,
a 4d tensor of shape `original_shape`.
Notes
-----
Currently, the function doesn't support tensors created with
`neib_step` different from default value. This means that it may be
impossible to compute the gradient of a variable gained by
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>` w.r.t.
its inputs in this case, because it uses
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>` for
gradient computation.
Examples
--------
Example, which uses a tensor gained in example for
:func:`images2neibs <theano.sandbox.neigbours.neibs2images>`:
...
...
@@ -555,6 +559,7 @@ def neibs2images(neibs, neib_shape, original_shape, mode='valid'):
im_new_val = inv_window(neibs_val)
.. note:: The code will output the initial image array.
"""
neibs
=
T
.
as_tensor_variable
(
neibs
)
neib_shape
=
T
.
as_tensor_variable
(
neib_shape
)
...
...
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