|
1
|
|
|
"""Bricks that are interfaces and/or mixins.""" |
|
2
|
|
|
import numpy |
|
3
|
|
|
from six import add_metaclass |
|
4
|
|
|
from theano.sandbox.rng_mrg import MRG_RandomStreams |
|
5
|
|
|
|
|
6
|
|
|
from ..config import config |
|
7
|
|
|
from .base import _Brick, Brick, lazy |
|
8
|
|
|
from blocks.roles import WEIGHT, BIAS, FILTER, INITIAL_STATE |
|
|
|
|
|
|
9
|
|
|
|
|
10
|
|
|
|
|
11
|
|
|
class ActivationDocumentation(_Brick): |
|
12
|
|
|
"""Dynamically adds documentation to activations. |
|
13
|
|
|
|
|
14
|
|
|
Notes |
|
15
|
|
|
----- |
|
16
|
|
|
See http://bugs.python.org/issue12773. |
|
17
|
|
|
|
|
18
|
|
|
""" |
|
19
|
|
|
def __new__(cls, name, bases, classdict): |
|
|
|
|
|
|
20
|
|
|
classdict['__doc__'] = \ |
|
21
|
|
|
"""Elementwise application of {0} function.""".format(name.lower()) |
|
22
|
|
|
if 'apply' in classdict: |
|
23
|
|
|
classdict['apply'].__doc__ = \ |
|
24
|
|
|
"""Apply the {0} function element-wise. |
|
25
|
|
|
|
|
26
|
|
|
Parameters |
|
27
|
|
|
---------- |
|
28
|
|
|
input_ : :class:`~tensor.TensorVariable` |
|
29
|
|
|
Theano variable to apply {0} to, element-wise. |
|
30
|
|
|
|
|
31
|
|
|
Returns |
|
32
|
|
|
------- |
|
33
|
|
|
output : :class:`~tensor.TensorVariable` |
|
34
|
|
|
The input with the activation function applied. |
|
35
|
|
|
|
|
36
|
|
|
""".format(name.lower()) |
|
37
|
|
|
return super(ActivationDocumentation, cls).__new__(cls, name, bases, |
|
38
|
|
|
classdict) |
|
39
|
|
|
|
|
40
|
|
|
|
|
41
|
|
|
@add_metaclass(ActivationDocumentation) |
|
42
|
|
|
class Activation(Brick): |
|
43
|
|
|
"""A base class for simple, element-wise activation functions. |
|
44
|
|
|
|
|
45
|
|
|
This base class ensures that activation functions are automatically |
|
46
|
|
|
documented using the :class:`ActivationDocumentation` metaclass. |
|
47
|
|
|
|
|
48
|
|
|
""" |
|
49
|
|
|
pass |
|
50
|
|
|
|
|
51
|
|
|
|
|
52
|
|
|
class Feedforward(Brick): |
|
53
|
|
|
"""Declares an interface for bricks with one input and one output. |
|
54
|
|
|
|
|
55
|
|
|
Many bricks have just one input and just one output (activations, |
|
56
|
|
|
:class:`Linear`, :class:`MLP`). To make such bricks interchangable |
|
57
|
|
|
in most contexts they should share an interface for configuring |
|
58
|
|
|
their input and output dimensions. This brick declares such an |
|
59
|
|
|
interface. |
|
60
|
|
|
|
|
61
|
|
|
Attributes |
|
62
|
|
|
---------- |
|
63
|
|
|
input_dim : int |
|
64
|
|
|
The input dimension of the brick. |
|
65
|
|
|
output_dim : int |
|
66
|
|
|
The output dimension of the brick. |
|
67
|
|
|
|
|
68
|
|
|
""" |
|
69
|
|
|
def __getattr__(self, name): |
|
70
|
|
|
message = ("'{}' object does not have an attribute '{}'" |
|
71
|
|
|
.format(self.__class__.__name__, name)) |
|
72
|
|
|
if name in ('input_dim', 'output_dim'): |
|
73
|
|
|
message += (" (which is a part of 'Feedforward' interface it" |
|
74
|
|
|
" claims to support)") |
|
75
|
|
|
raise AttributeError(message) |
|
76
|
|
|
|
|
77
|
|
|
|
|
78
|
|
|
class RNGMixin(object): |
|
79
|
|
|
"""Mixin for initialization random number generators.""" |
|
80
|
|
|
seed_rng = numpy.random.RandomState(config.default_seed) |
|
81
|
|
|
|
|
82
|
|
|
@property |
|
83
|
|
|
def seed(self): |
|
84
|
|
|
if getattr(self, '_seed', None) is not None: |
|
85
|
|
|
return self._seed |
|
86
|
|
|
else: |
|
87
|
|
|
self._seed = self.seed_rng.randint( |
|
88
|
|
|
numpy.iinfo(numpy.int32).max) |
|
89
|
|
|
return self._seed |
|
90
|
|
|
|
|
91
|
|
|
@seed.setter |
|
92
|
|
|
def seed(self, value): |
|
93
|
|
|
if hasattr(self, '_seed'): |
|
94
|
|
|
raise AttributeError("seed already set") |
|
95
|
|
|
self._seed = value |
|
96
|
|
|
|
|
97
|
|
|
@property |
|
98
|
|
|
def rng(self): |
|
99
|
|
|
if getattr(self, '_rng', None) is not None: |
|
100
|
|
|
return self._rng |
|
101
|
|
|
else: |
|
102
|
|
|
self._rng = numpy.random.RandomState(self.seed) |
|
103
|
|
|
return self._rng |
|
104
|
|
|
|
|
105
|
|
|
@rng.setter |
|
106
|
|
|
def rng(self, rng): |
|
107
|
|
|
self._rng = rng |
|
108
|
|
|
|
|
109
|
|
|
|
|
110
|
|
|
class Initializable(RNGMixin, Brick): |
|
111
|
|
|
"""Base class for bricks which push parameter initialization. |
|
112
|
|
|
|
|
113
|
|
|
Many bricks will initialize children which perform a linear |
|
114
|
|
|
transformation, often with biases. This brick allows the weights |
|
115
|
|
|
and biases initialization to be configured in the parent brick and |
|
116
|
|
|
pushed down the hierarchy. |
|
117
|
|
|
|
|
118
|
|
|
Parameters |
|
119
|
|
|
---------- |
|
120
|
|
|
weights_init : object |
|
121
|
|
|
A `NdarrayInitialization` instance which will be used by to |
|
122
|
|
|
initialize the weight matrix. Required by |
|
123
|
|
|
:meth:`~.Brick.initialize`. |
|
124
|
|
|
biases_init : :obj:`object`, optional |
|
125
|
|
|
A `NdarrayInitialization` instance that will be used to initialize |
|
126
|
|
|
the biases. Required by :meth:`~.Brick.initialize` when `use_bias` |
|
127
|
|
|
is `True`. Only supported by bricks for which :attr:`has_biases` is |
|
128
|
|
|
``True``. |
|
129
|
|
|
use_bias : :obj:`bool`, optional |
|
130
|
|
|
Whether to use a bias. Defaults to `True`. Required by |
|
131
|
|
|
:meth:`~.Brick.initialize`. |
|
132
|
|
|
rng : :class:`numpy.random.RandomState` |
|
133
|
|
|
|
|
134
|
|
|
""" |
|
135
|
|
|
|
|
136
|
|
|
@lazy() |
|
137
|
|
|
def __init__(self, initialization_schemes=None, parameter_roles=None, |
|
138
|
|
|
use_bias=True, seed=None, **kwargs): |
|
139
|
|
|
self.use_bias = use_bias |
|
140
|
|
|
self.seed = seed |
|
141
|
|
|
self.initialization_schemes = initialization_schemes |
|
142
|
|
|
if self.initialization_schemes is None: |
|
143
|
|
|
self.initialization_schemes = {} |
|
144
|
|
|
|
|
145
|
|
|
if parameter_roles: |
|
146
|
|
|
self.parameter_roles = parameter_roles |
|
147
|
|
|
else: |
|
148
|
|
|
self.parameter_roles = set([WEIGHT]) |
|
149
|
|
|
if use_bias: |
|
150
|
|
|
self.parameter_roles.update(set([BIAS])) |
|
151
|
|
|
|
|
152
|
|
|
initialization_to_role = {"weights_init": WEIGHT, 'biases_init': BIAS, |
|
153
|
|
|
'initial_state_init': INITIAL_STATE} |
|
154
|
|
|
for key in list(kwargs.keys()): |
|
155
|
|
|
if key[-5:] == "_init": |
|
156
|
|
|
if key not in initialization_to_role: |
|
157
|
|
|
raise ValueError("The initlization scheme: {}".format(key), |
|
158
|
|
|
"is not defined by default, pass it" |
|
159
|
|
|
"via initialization_schemes") |
|
160
|
|
|
if initialization_to_role[key] in \ |
|
161
|
|
|
self.initialization_schemes.keys(): |
|
162
|
|
|
raise ValueError("All initializations are accepted either" |
|
163
|
|
|
"through initialization schemes or " |
|
164
|
|
|
"corresponding attribute but not both") |
|
165
|
|
|
else: |
|
166
|
|
|
self.initialization_schemes[initialization_to_role[ |
|
167
|
|
|
key]] = kwargs[key] |
|
168
|
|
|
kwargs.pop(key) |
|
169
|
|
|
|
|
170
|
|
|
super(Initializable, self).__init__(**kwargs) |
|
171
|
|
|
self._collect_roles() |
|
172
|
|
|
|
|
173
|
|
|
def _validate_roles(self): |
|
174
|
|
|
high_level_roles = [] |
|
175
|
|
|
for role in self.parameter_roles: |
|
176
|
|
|
if role not in self.initialization_schemes.keys(): |
|
177
|
|
|
for key in list(self.initialization_schemes.keys()): |
|
178
|
|
|
if isinstance(role, type(key)): |
|
179
|
|
|
self.initialization_schemes[role] = \ |
|
180
|
|
|
self.initialization_schemes[key] |
|
181
|
|
|
high_level_roles.append(key) |
|
182
|
|
|
|
|
183
|
|
|
for key in high_level_roles: |
|
184
|
|
|
if key not in self.parameter_roles: |
|
185
|
|
|
self.initialization_schemes.pop(key) |
|
186
|
|
|
|
|
187
|
|
|
for key in self.initialization_schemes: |
|
188
|
|
|
if key not in self.parameter_roles: |
|
189
|
|
|
raise ValueError("{} is not member of ".format(key) + |
|
190
|
|
|
"parameter_roles") |
|
191
|
|
|
|
|
192
|
|
|
def _push_initialization_config(self): |
|
193
|
|
|
self._validate_roles() |
|
194
|
|
|
for child in self.children: |
|
195
|
|
|
if (isinstance(child, Initializable) and |
|
196
|
|
|
hasattr(child, 'initialization_schemes')): |
|
197
|
|
|
child.rng = self.rng |
|
198
|
|
|
for role, scheme in self.initialization_schemes.items(): |
|
199
|
|
|
if role in child.parameter_roles: |
|
200
|
|
|
child.initialization_schemes[role] = scheme |
|
201
|
|
|
|
|
202
|
|
|
def _collect_roles(self): |
|
203
|
|
|
for child in self.children: |
|
204
|
|
|
if isinstance(child, Initializable): |
|
205
|
|
|
self.parameter_roles.update(child.parameter_roles) |
|
206
|
|
|
|
|
207
|
|
|
def _initialize(self): |
|
208
|
|
|
for param in self.parameters: |
|
209
|
|
|
for role in param.tag.roles: |
|
210
|
|
|
if role in self.parameter_roles: |
|
211
|
|
|
self.initialization_schemes[role].initialize(param, |
|
212
|
|
|
self.rng) |
|
213
|
|
|
|
|
214
|
|
|
def __getattr__(self, name): |
|
215
|
|
|
if name == "weights_init": |
|
216
|
|
|
if WEIGHT in self.initialization_schemes: |
|
217
|
|
|
return self.initialization_schemes[WEIGHT] |
|
218
|
|
|
elif name == "biases_init": |
|
219
|
|
|
if BIAS in self.initialization_schemes: |
|
220
|
|
|
return self.initialization_schemes[BIAS] |
|
221
|
|
|
super(Initializable, self).__getattr__(name) |
|
222
|
|
|
|
|
223
|
|
|
def __setattr__(self, name, value): |
|
224
|
|
|
if name == 'weights_init': |
|
225
|
|
|
self.initialization_schemes[WEIGHT] = value |
|
226
|
|
|
elif name == 'biases_init': |
|
227
|
|
|
self.initialization_schemes[BIAS] = value |
|
228
|
|
|
else: |
|
229
|
|
|
super(Initializable, self).__setattr__(name, value) |
|
230
|
|
|
|
|
231
|
|
|
|
|
232
|
|
|
class LinearLike(Initializable): |
|
233
|
|
|
"""Initializable subclass with logic for :class:`Linear`-like classes. |
|
234
|
|
|
|
|
235
|
|
|
Notes |
|
236
|
|
|
----- |
|
237
|
|
|
Provides `W` and `b` properties that can be overridden in subclasses |
|
238
|
|
|
to implement pre-application transformations on the weights and |
|
239
|
|
|
biases. Application methods should refer to ``self.W`` and ``self.b`` |
|
240
|
|
|
rather than accessing the parameters list directly. |
|
241
|
|
|
|
|
242
|
|
|
This assumes a layout of the parameters list with the weights coming |
|
243
|
|
|
first and biases (if ``use_bias`` is True) coming second. |
|
244
|
|
|
|
|
245
|
|
|
""" |
|
246
|
|
|
|
|
247
|
|
|
def __init__(self, **kwargs): |
|
248
|
|
|
if 'parameter_roles' in kwargs: |
|
249
|
|
|
kwargs['parameter_roles'].update(set([WEIGHT, BIAS])) |
|
250
|
|
|
else: |
|
251
|
|
|
kwargs['parameter_roles'] = set([WEIGHT, BIAS]) |
|
252
|
|
|
super(LinearLike, self).__init__(**kwargs) |
|
253
|
|
|
|
|
254
|
|
|
@property |
|
255
|
|
|
def W(self): |
|
256
|
|
|
return self.parameters[0] |
|
257
|
|
|
|
|
258
|
|
|
@property |
|
259
|
|
|
def b(self): |
|
260
|
|
|
if getattr(self, 'use_bias', True): |
|
261
|
|
|
return self.parameters[1] |
|
262
|
|
|
else: |
|
263
|
|
|
raise AttributeError('use_bias is False') |
|
264
|
|
|
|
|
265
|
|
|
|
|
266
|
|
|
class Random(Brick): |
|
267
|
|
|
"""A mixin class for Bricks which need Theano RNGs. |
|
268
|
|
|
|
|
269
|
|
|
Parameters |
|
270
|
|
|
---------- |
|
271
|
|
|
theano_seed : int or list, optional |
|
272
|
|
|
Seed to use for a |
|
273
|
|
|
:class:`~theano.sandbox.rng_mrg.MRG_RandomStreams` object. |
|
274
|
|
|
|
|
275
|
|
|
""" |
|
276
|
|
|
seed_rng = numpy.random.RandomState(config.default_seed) |
|
277
|
|
|
|
|
278
|
|
|
def __init__(self, theano_seed=None, **kwargs): |
|
279
|
|
|
super(Random, self).__init__(**kwargs) |
|
280
|
|
|
self.theano_seed = theano_seed |
|
281
|
|
|
|
|
282
|
|
|
@property |
|
283
|
|
|
def theano_seed(self): |
|
284
|
|
|
if getattr(self, '_theano_seed', None) is not None: |
|
285
|
|
|
return self._theano_seed |
|
286
|
|
|
else: |
|
287
|
|
|
self._theano_seed = self.seed_rng.randint( |
|
288
|
|
|
numpy.iinfo(numpy.int32).max) |
|
289
|
|
|
return self._theano_seed |
|
290
|
|
|
|
|
291
|
|
|
@theano_seed.setter |
|
292
|
|
|
def theano_seed(self, value): |
|
293
|
|
|
if hasattr(self, '_theano_seed'): |
|
294
|
|
|
raise AttributeError("seed already set") |
|
295
|
|
|
self._theano_seed = value |
|
296
|
|
|
|
|
297
|
|
|
@property |
|
298
|
|
|
def theano_rng(self): |
|
299
|
|
|
"""Returns Brick's Theano RNG, or a default one. |
|
300
|
|
|
|
|
301
|
|
|
The default seed can be set through ``blocks.config``. |
|
302
|
|
|
|
|
303
|
|
|
""" |
|
304
|
|
|
if not hasattr(self, '_theano_rng'): |
|
305
|
|
|
self._theano_rng = MRG_RandomStreams(self.theano_seed) |
|
306
|
|
|
return self._theano_rng |
|
307
|
|
|
|
|
308
|
|
|
@theano_rng.setter |
|
309
|
|
|
def theano_rng(self, theano_rng): |
|
310
|
|
|
self._theano_rng = theano_rng |
|
311
|
|
|
|