Jensun Ravichandran 8a291f7bfb Overload distribution argument in component initializers
The component initializers behave differently based on the type of the
`distribution` argument. If it is a Python
[list](https://docs.python.org/3/tutorial/datastructures.html), it is assumed
that there are as many entries in this list as there are classes, and the number
at each location of this list describes the number of prototypes to be used for
that particular class. So, `[1, 1, 1]` implies that we have three classes with
one prototype per class. If it is a Python
[tuple](https://docs.python.org/3/tutorial/datastructures.html), it a shorthand
of `(num_classes, prototypes_per_class)` is assumed. If it is a Python
[dictionary](https://docs.python.org/3/tutorial/datastructures.html), the
key-value pairs describe the class label and the number of prototypes for that
class respectively. So, `{0: 2, 1: 2, 2: 2}` implies that we have three classes
with labels `{1, 2, 3}`, each equipped with two prototypes.
2021-05-25 20:05:29 +02:00

162 lines
6.0 KiB
Python

"""ProtoTorch components modules."""
import warnings
import torch
from prototorch.components.initializers import (ClassAwareInitializer,
ComponentsInitializer,
CustomLabelsInitializer,
EqualLabelsInitializer,
UnequalLabelsInitializer,
ZeroReasoningsInitializer)
from torch.nn.parameter import Parameter
class Components(torch.nn.Module):
"""Components is a set of learnable Tensors."""
def __init__(self,
num_components=None,
initializer=None,
*,
initialized_components=None):
super().__init__()
self.num_components = num_components
# Ignore all initialization settings if initialized_components is given.
if initialized_components is not None:
self.register_parameter("_components",
Parameter(initialized_components))
if num_components is not None or initializer is not None:
wmsg = "Arguments ignored while initializing Components"
warnings.warn(wmsg)
else:
self._initialize_components(initializer)
def _precheck_initializer(self, initializer):
if not isinstance(initializer, ComponentsInitializer):
emsg = f"`initializer` has to be some subtype of " \
f"{ComponentsInitializer}. " \
f"You have provided: {initializer=} instead."
raise TypeError(emsg)
def _initialize_components(self, initializer):
self._precheck_initializer(initializer)
_components = initializer.generate(self.num_components)
self.register_parameter("_components", Parameter(_components))
@property
def components(self):
"""Tensor containing the component tensors."""
return self._components.detach()
def forward(self):
return self._components
def extra_repr(self):
return f"components.shape: {tuple(self._components.shape)}"
class LabeledComponents(Components):
"""LabeledComponents generate a set of components and a set of labels.
Every Component has a label assigned.
"""
def __init__(self,
distribution=None,
initializer=None,
*,
initialized_components=None):
if initialized_components is not None:
components, component_labels = initialized_components
super().__init__(initialized_components=components)
self._labels = component_labels
else:
_labels = self._initialize_labels(distribution)
super().__init__(len(_labels), initializer=initializer)
self.register_buffer("_labels", _labels)
def _initialize_components(self, initializer):
if isinstance(initializer, ClassAwareInitializer):
self._precheck_initializer(initializer)
_components = initializer.generate(self.num_components,
self.distribution)
self.register_parameter("_components", Parameter(_components))
else:
super()._initialize_components(initializer)
def _initialize_labels(self, distribution):
if type(distribution) == dict:
if "num_classes" in distribution.keys():
labels = EqualLabelsInitializer(
distribution["num_classes"],
distribution["prototypes_per_class"])
else:
labels = CustomLabelsInitializer(distribution)
elif type(distribution) == tuple:
num_classes, prototypes_per_class = distribution
labels = EqualLabelsInitializer(num_classes, prototypes_per_class)
elif type(distribution) == list:
labels = UnequalLabelsInitializer(distribution)
self.distribution = labels.distribution
return labels.generate()
@property
def component_labels(self):
"""Tensor containing the component tensors."""
return self._labels.detach()
def forward(self):
return super().forward(), self._labels
class ReasoningComponents(Components):
"""ReasoningComponents generate a set of components and a set of reasoning matrices.
Every Component has a reasoning matrix assigned.
A reasoning matrix is a Nx2 matrix, where N is the number of Classes. The
first element is called positive reasoning :math:`p`, the second negative
reasoning :math:`n`. A components can reason in favour (positive) of a
class, against (negative) a class or not at all (neutral).
It holds that :math:`0 \leq n \leq 1`, :math:`0 \leq p \leq 1` and :math:`0
\leq n+p \leq 1`. Therefore :math:`n` and :math:`p` are two elements of a
three element probability distribution.
"""
def __init__(self,
reasonings=None,
initializer=None,
*,
initialized_components=None):
if initialized_components is not None:
components, reasonings = initialized_components
super().__init__(initialized_components=components)
self.register_parameter("_reasonings", reasonings)
else:
self._initialize_reasonings(reasonings)
super().__init__(len(self._reasonings), initializer=initializer)
def _initialize_reasonings(self, reasonings):
if type(reasonings) == tuple:
num_classes, num_components = reasonings
reasonings = ZeroReasoningsInitializer(num_classes, num_components)
_reasonings = reasonings.generate()
self.register_parameter("_reasonings", _reasonings)
@property
def reasonings(self):
"""Returns Reasoning Matrix.
Dimension NxCx2
"""
return self._reasonings.detach()
def forward(self):
return super().forward(), self._reasonings