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759 lines
34 KiB
759 lines
34 KiB
5 months ago
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import torch
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from torch.nn.modules.container import ModuleList, ModuleDict, Module
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from torch.nn.parameter import Parameter
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from torch import Tensor
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import collections
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import copyreg
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from copy import deepcopy
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from contextlib import contextmanager
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from typing import Union, Optional, Dict, Tuple, Sequence
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__all__ = ['cached', 'ParametrizationList', 'register_parametrization', 'is_parametrized', 'remove_parametrizations',
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'type_before_parametrizations', 'transfer_parametrizations_and_params']
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_cache_enabled = 0
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_cache: Dict[Tuple[int, str], Optional[Tensor]] = {}
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@contextmanager
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def cached():
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r"""Context manager that enables the caching system within parametrizations registered with :func:`register_parametrization`.
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The value of the parametrized objects is computed and cached the first time
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they are required when this context manager is active. The cached values are
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discarded when leaving the context manager.
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This is useful when using a parametrized parameter more than once in the forward pass.
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An example of this is when parametrizing the recurrent kernel of an RNN or when
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sharing weights.
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The simplest way to activate the cache is by wrapping the forward pass of the neural network
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.. code-block:: python
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import torch.nn.utils.parametrize as P
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...
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with P.cached():
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output = model(inputs)
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in training and evaluation. One may also wrap the parts of the modules that use
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several times the parametrized tensors. For example, the loop of an RNN with a
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parametrized recurrent kernel:
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.. code-block:: python
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with P.cached():
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for x in xs:
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out_rnn = self.rnn_cell(x, out_rnn)
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"""
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global _cache
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global _cache_enabled
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_cache_enabled += 1
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try:
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yield
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finally:
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_cache_enabled -= 1
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if not _cache_enabled:
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_cache = {}
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def _register_parameter_or_buffer(module, name, X):
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if isinstance(X, Parameter):
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module.register_parameter(name, X)
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else:
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module.register_buffer(name, X)
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class ParametrizationList(ModuleList):
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r"""A sequential container that holds and manages the original parameters or buffers of a parametrized :class:`torch.nn.Module`.
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It is the type of ``module.parametrizations[tensor_name]`` when ``module[tensor_name]``
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has been parametrized with :func:`register_parametrization`.
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If the first registered parametrization has a ``right_inverse`` that returns one tensor or
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does not have a ``right_inverse`` (in which case we assume that ``right_inverse`` is the identity),
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it will hold the tensor under the name ``original``.
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If it has a ``right_inverse`` that returns more than one tensor, these will be registered as
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``original0``, ``original1``, ...
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.. warning::
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This class is used internally by :func:`register_parametrization`. It is documented
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here for completeness. It shall not be instantiated by the user.
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Args:
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modules (sequence): sequence of modules representing the parametrizations
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original (Parameter or Tensor): parameter or buffer that is parametrized
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unsafe (bool): a boolean flag that denotes whether the parametrization
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may change the dtype and shape of the tensor. Default: `False`
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Warning: the parametrization is not checked for consistency upon registration.
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Enable this flag at your own risk.
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"""
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original: Tensor
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unsafe: bool
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def __init__(
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self, modules: Sequence[Module], original: Union[Tensor, Parameter], unsafe: bool = False
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) -> None:
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# We require this because we need to treat differently the first parametrization
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# This should never throw, unless this class is used from the outside
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if len(modules) == 0:
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raise ValueError("ParametrizationList requires one or more modules.")
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super().__init__(modules)
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self.unsafe = unsafe
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# In plain words:
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# module.weight must keep its dtype and shape.
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# Furthermore, if there is no right_inverse or the right_inverse returns a tensor,
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# this should be of the same dtype as the original tensor
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#
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# We check that the following invariants hold:
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# X = module.weight
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# Y = param.right_inverse(X)
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# assert isinstance(Y, Tensor) or
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# (isinstance(Y, collections.abc.Sequence) and all(isinstance(t, Tensor) for t in Y))
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# Z = param(Y) if isinstance(Y, Tensor) else param(*Y)
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# # Consistency checks
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# assert X.dtype == Z.dtype and X.shape == Z.shape
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# # If it has one input, this allows to be able to use set_ to be able to
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# # move data to/from the original tensor without changing its id (which is what the
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# # optimizer uses to track parameters)
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# if isinstance(Y, Tensor)
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# assert X.dtype == Y.dtype
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# Below we use original = X, new = Y
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original_shape = original.shape
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original_dtype = original.dtype
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# Compute new
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with torch.no_grad():
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new = original
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for module in reversed(self): # type: ignore[call-overload]
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if hasattr(module, "right_inverse"):
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try:
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new = module.right_inverse(new)
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except NotImplementedError:
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pass
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# else, or if it throws, we assume that right_inverse is the identity
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if not isinstance(new, Tensor) and not isinstance(new, collections.abc.Sequence):
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raise ValueError("'right_inverse' must return a Tensor or a Sequence of tensors (list, tuple...). "
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f"Got {type(new).__name__}")
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# Set the number of original tensors
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self.is_tensor = isinstance(new, Tensor)
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self.ntensors = 1 if self.is_tensor else len(new)
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# Register the tensor(s)
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if self.is_tensor:
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if original.dtype != new.dtype:
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raise ValueError(
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"When `right_inverse` outputs one tensor, it may not change the dtype.\n"
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f"original.dtype: {original.dtype}\n"
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f"right_inverse(original).dtype: {new.dtype}"
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)
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# Set the original to original so that the user does not need to re-register the parameter
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# manually in the optimiser
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with torch.no_grad():
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original.set_(new) # type: ignore[call-overload]
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_register_parameter_or_buffer(self, "original", original)
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else:
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for i, originali in enumerate(new):
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if not isinstance(originali, Tensor):
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raise ValueError("'right_inverse' must return a Tensor or a Sequence of tensors "
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"(list, tuple...). "
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f"Got element {i} of the sequence with type {type(originali).__name__}.")
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# If the original tensor was a Parameter that required grad, we expect the user to
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# add the new parameters to the optimizer after registering the parametrization
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# (this is documented)
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if isinstance(original, Parameter):
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originali = Parameter(originali)
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originali.requires_grad_(original.requires_grad)
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_register_parameter_or_buffer(self, f"original{i}", originali)
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if not self.unsafe:
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# Consistency checks:
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# Since f : A -> B, right_inverse : B -> A, Z and original should live in B
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# Z = forward(right_inverse(original))
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Z = self()
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if not isinstance(Z, Tensor):
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raise ValueError(
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f"A parametrization must return a tensor. Got {type(Z).__name__}."
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)
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if Z.dtype != original_dtype:
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raise ValueError(
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"Registering a parametrization may not change the dtype of the tensor, unless `unsafe` flag is enabled.\n"
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f"unparametrized dtype: {original_dtype}\n"
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f"parametrized dtype: {Z.dtype}"
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)
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if Z.shape != original_shape:
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raise ValueError(
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"Registering a parametrization may not change the shape of the tensor, unless `unsafe` flag is enabled.\n"
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f"unparametrized shape: {original_shape}\n"
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f"parametrized shape: {Z.shape}"
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)
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def right_inverse(self, value: Tensor) -> None:
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r"""Call the ``right_inverse`` methods of the parametrizations in the inverse registration order.
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Then, it stores the result in ``self.original`` if ``right_inverse`` outputs one tensor
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or in ``self.original0``, ``self.original1``, ... if it outputs several.
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Args:
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value (Tensor): Value to which initialize the module
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"""
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# All the exceptions in this function should almost never throw.
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# They could throw if, for example, right_inverse function returns a different
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# dtype when given a different input, which should most likely be caused by a
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# bug in the user's code
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with torch.no_grad():
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# See https://github.com/pytorch/pytorch/issues/53103
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for module in reversed(self): # type: ignore[call-overload]
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if hasattr(module, "right_inverse"):
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value = module.right_inverse(value)
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else:
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raise RuntimeError(f"parametrization {type(module).__name__} does not implement "
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"right_inverse.")
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if self.is_tensor:
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# These exceptions should only throw when a right_inverse function does not
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# return the same dtype for every input, which should most likely be caused by a bug
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if not isinstance(value, Tensor):
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raise ValueError(
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f"`right_inverse` should return a tensor. Got {type(value).__name__}"
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)
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if value.dtype != self.original.dtype:
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raise ValueError(
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f"The tensor returned by `right_inverse` has dtype {value.dtype} "
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f"while `original` has dtype {self.original.dtype}"
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)
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# We know that the result is going to have the same dtype
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self.original.set_(value) # type: ignore[call-overload]
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else:
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if not isinstance(value, collections.abc.Sequence):
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raise ValueError(
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"'right_inverse' must return a sequence of tensors. "
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f"Got {type(value).__name__}."
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)
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if len(value) != self.ntensors:
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raise ValueError(
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"'right_inverse' must return a sequence of tensors of length "
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f"{self.ntensors}. Got a sequence of length {len(value)}."
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)
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for i, tensor in enumerate(value):
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original_i = getattr(self, f"original{i}")
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if not isinstance(tensor, Tensor):
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raise ValueError(
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f"`right_inverse` must return a sequence of tensors. "
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f"Got element {i} of type {type(tensor).__name__}"
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)
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if original_i.dtype != tensor.dtype:
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raise ValueError(
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f"Tensor {i} returned by `right_inverse` has dtype {tensor.dtype} "
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f"while `original{i}` has dtype {original_i.dtype}"
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)
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original_i.set_(tensor)
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def forward(self) -> Tensor:
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if torch.jit.is_scripting():
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raise RuntimeError('Parametrization is not working with scripting.')
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# Unpack the originals for the first parametrization
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if self.is_tensor:
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x = self[0](self.original)
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else:
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originals = (getattr(self, f"original{i}") for i in range(self.ntensors))
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x = self[0](*originals)
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# It's not possible to call self[1:] here, so we have to be a bit more cryptic
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# Also we want to skip all non-integer keys
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curr_idx = 1
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while hasattr(self, str(curr_idx)):
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x = self[curr_idx](x)
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curr_idx += 1
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return x
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def _inject_new_class(module: Module) -> None:
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r"""Set up a module to be parametrized.
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This works by substituting the class of the module by a class
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that extends it to be able to inject a property
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Args:
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module (nn.Module): module into which to inject the property
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"""
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cls = module.__class__
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def default_deepcopy(self, memo):
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# Just emulate a standard deepcopy procedure when __deepcopy__ doesn't exist in the current class.
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obj = memo.get(id(self), None)
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if obj is not None:
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return obj
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replica = self.__new__(self.__class__)
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memo[id(self)] = replica
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replica.__dict__ = deepcopy(self.__dict__, memo)
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# Also save all slots if they exist.
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slots_to_save = copyreg._slotnames(self.__class__) # type: ignore[attr-defined]
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for slot in slots_to_save:
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if hasattr(self, slot):
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setattr(replica, slot, deepcopy(getattr(self, slot), memo))
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return replica
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def getstate(self):
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raise RuntimeError(
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"Serialization of parametrized modules is only "
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"supported through state_dict(). See:\n"
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"https://pytorch.org/tutorials/beginner/saving_loading_models.html"
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"#saving-loading-a-general-checkpoint-for-inference-and-or-resuming-training"
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)
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dct = {"__getstate__": getstate}
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# We don't allow serialization of parametrized modules but should still allow deepcopying.
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# Default 'deepcopy' function invokes __deepcopy__ method instead of __getstate__ when it exists.
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if not hasattr(cls, "__deepcopy__"):
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dct["__deepcopy__"] = default_deepcopy # type: ignore[assignment]
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param_cls = type(
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f"Parametrized{cls.__name__}",
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(cls,),
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dct,
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)
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module.__class__ = param_cls
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def _inject_property(module: Module, tensor_name: str) -> None:
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r"""Injects a property into module[tensor_name].
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It assumes that the class in the module has already been modified from its
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original one using _inject_new_class and that the tensor under :attr:`tensor_name`
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has already been moved out
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Args:
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module (nn.Module): module into which to inject the property
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tensor_name (str): name of the name of the property to create
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"""
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# We check the precondition.
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# This should never fire if register_parametrization is correctly implemented
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assert not hasattr(module, tensor_name)
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@torch.jit.unused
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def get_cached_parametrization(parametrization) -> Tensor:
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global _cache
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key = (id(module), tensor_name)
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tensor = _cache.get(key)
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if tensor is None:
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tensor = parametrization()
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_cache[key] = tensor
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return tensor
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def get_parametrized(self) -> Tensor:
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if torch.jit.is_scripting():
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raise RuntimeError('Parametrization is not working with scripting.')
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parametrization = self.parametrizations[tensor_name]
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||
|
|
if _cache_enabled:
|
||
|
|
if torch.jit.is_scripting():
|
||
|
|
# Scripting
|
||
|
|
raise RuntimeError('Caching is not implemented for scripting. '
|
||
|
|
'Either disable caching or avoid scripting.')
|
||
|
|
elif torch._C._get_tracing_state() is not None:
|
||
|
|
# Tracing
|
||
|
|
raise RuntimeError('Cannot trace a model while caching parametrizations.')
|
||
|
|
else:
|
||
|
|
return get_cached_parametrization(parametrization)
|
||
|
|
else:
|
||
|
|
# If caching is not active, this function just evaluates the parametrization
|
||
|
|
return parametrization()
|
||
|
|
|
||
|
|
def set_original(self, value: Tensor) -> None:
|
||
|
|
if torch.jit.is_scripting():
|
||
|
|
raise RuntimeError('Parametrization is not working with scripting.')
|
||
|
|
self.parametrizations[tensor_name].right_inverse(value)
|
||
|
|
|
||
|
|
setattr(module.__class__, tensor_name, property(get_parametrized, set_original))
|
||
|
|
|
||
|
|
def register_parametrization(
|
||
|
|
module: Module, tensor_name: str, parametrization: Module, *, unsafe: bool = False,
|
||
|
|
) -> Module:
|
||
|
|
r"""Register a parametrization to a tensor in a module.
|
||
|
|
|
||
|
|
Assume that ``tensor_name="weight"`` for simplicity. When accessing ``module.weight``,
|
||
|
|
the module will return the parametrized version ``parametrization(module.weight)``.
|
||
|
|
If the original tensor requires a gradient, the backward pass will differentiate
|
||
|
|
through :attr:`parametrization`, and the optimizer will update the tensor accordingly.
|
||
|
|
|
||
|
|
The first time that a module registers a parametrization, this function will add an attribute
|
||
|
|
``parametrizations`` to the module of type :class:`~ParametrizationList`.
|
||
|
|
|
||
|
|
The list of parametrizations on the tensor ``weight`` will be accessible under
|
||
|
|
``module.parametrizations.weight``.
|
||
|
|
|
||
|
|
The original tensor will be accessible under
|
||
|
|
``module.parametrizations.weight.original``.
|
||
|
|
|
||
|
|
Parametrizations may be concatenated by registering several parametrizations
|
||
|
|
on the same attribute.
|
||
|
|
|
||
|
|
The training mode of a registered parametrization is updated on registration
|
||
|
|
to match the training mode of the host module
|
||
|
|
|
||
|
|
Parametrized parameters and buffers have an inbuilt caching system that can be activated
|
||
|
|
using the context manager :func:`cached`.
|
||
|
|
|
||
|
|
A :attr:`parametrization` may optionally implement a method with signature
|
||
|
|
|
||
|
|
.. code-block:: python
|
||
|
|
|
||
|
|
def right_inverse(self, X: Tensor) -> Union[Tensor, Sequence[Tensor]]
|
||
|
|
|
||
|
|
This method is called on the unparametrized tensor when the first parametrization
|
||
|
|
is registered to compute the initial value of the original tensor.
|
||
|
|
If this method is not implemented, the original tensor will be just the unparametrized tensor.
|
||
|
|
|
||
|
|
If all the parametrizations registered on a tensor implement `right_inverse` it is possible
|
||
|
|
to initialize a parametrized tensor by assigning to it, as shown in the example below.
|
||
|
|
|
||
|
|
It is possible for the first parametrization to depend on several inputs.
|
||
|
|
This may be implemented returning a tuple of tensors from ``right_inverse``
|
||
|
|
(see the example implementation of a ``RankOne`` parametrization below).
|
||
|
|
|
||
|
|
In this case, the unconstrained tensors are also located under ``module.parametrizations.weight``
|
||
|
|
with names ``original0``, ``original1``,...
|
||
|
|
|
||
|
|
.. note::
|
||
|
|
|
||
|
|
If unsafe=False (default) both the forward and right_inverse methods will be called
|
||
|
|
once to perform a number of consistency checks.
|
||
|
|
If unsafe=True, then right_inverse will be called if the tensor is not parametrized,
|
||
|
|
and nothing will be called otherwise.
|
||
|
|
|
||
|
|
.. note::
|
||
|
|
|
||
|
|
In most situations, ``right_inverse`` will be a function such that
|
||
|
|
``forward(right_inverse(X)) == X`` (see
|
||
|
|
`right inverse <https://en.wikipedia.org/wiki/Inverse_function#Right_inverses>`_).
|
||
|
|
Sometimes, when the parametrization is not surjective, it may be reasonable
|
||
|
|
to relax this.
|
||
|
|
|
||
|
|
.. warning::
|
||
|
|
|
||
|
|
If a parametrization depends on several inputs, :func:`~register_parametrization`
|
||
|
|
will register a number of new parameters. If such parametrization is registered
|
||
|
|
after the optimizer is created, these new parameters will need to be added manually
|
||
|
|
to the optimizer. See :meth:`torch.Optimizer.add_param_group`.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
module (nn.Module): module on which to register the parametrization
|
||
|
|
tensor_name (str): name of the parameter or buffer on which to register
|
||
|
|
the parametrization
|
||
|
|
parametrization (nn.Module): the parametrization to register
|
||
|
|
Keyword args:
|
||
|
|
unsafe (bool): a boolean flag that denotes whether the parametrization
|
||
|
|
may change the dtype and shape of the tensor. Default: `False`
|
||
|
|
Warning: the parametrization is not checked for consistency upon registration.
|
||
|
|
Enable this flag at your own risk.
|
||
|
|
|
||
|
|
Raises:
|
||
|
|
ValueError: if the module does not have a parameter or a buffer named :attr:`tensor_name`
|
||
|
|
|
||
|
|
Examples:
|
||
|
|
>>> # xdoctest: +REQUIRES(env:TORCH_DOCTEST_LAPACK)
|
||
|
|
>>> import torch
|
||
|
|
>>> import torch.nn as nn
|
||
|
|
>>> import torch.nn.utils.parametrize as P
|
||
|
|
>>>
|
||
|
|
>>> class Symmetric(nn.Module):
|
||
|
|
>>> def forward(self, X):
|
||
|
|
>>> return X.triu() + X.triu(1).T # Return a symmetric matrix
|
||
|
|
>>>
|
||
|
|
>>> def right_inverse(self, A):
|
||
|
|
>>> return A.triu()
|
||
|
|
>>>
|
||
|
|
>>> m = nn.Linear(5, 5)
|
||
|
|
>>> P.register_parametrization(m, "weight", Symmetric())
|
||
|
|
>>> print(torch.allclose(m.weight, m.weight.T)) # m.weight is now symmetric
|
||
|
|
True
|
||
|
|
>>> A = torch.rand(5, 5)
|
||
|
|
>>> A = A + A.T # A is now symmetric
|
||
|
|
>>> m.weight = A # Initialize the weight to be the symmetric matrix A
|
||
|
|
>>> print(torch.allclose(m.weight, A))
|
||
|
|
True
|
||
|
|
|
||
|
|
>>> class RankOne(nn.Module):
|
||
|
|
>>> def forward(self, x, y):
|
||
|
|
>>> # Form a rank 1 matrix multiplying two vectors
|
||
|
|
>>> return x.unsqueeze(-1) @ y.unsqueeze(-2)
|
||
|
|
>>>
|
||
|
|
>>> def right_inverse(self, Z):
|
||
|
|
>>> # Project Z onto the rank 1 matrices
|
||
|
|
>>> U, S, Vh = torch.linalg.svd(Z, full_matrices=False)
|
||
|
|
>>> # Return rescaled singular vectors
|
||
|
|
>>> s0_sqrt = S[0].sqrt().unsqueeze(-1)
|
||
|
|
>>> return U[..., :, 0] * s0_sqrt, Vh[..., 0, :] * s0_sqrt
|
||
|
|
>>>
|
||
|
|
>>> linear_rank_one = P.register_parametrization(nn.Linear(4, 4), "weight", RankOne())
|
||
|
|
>>> print(torch.linalg.matrix_rank(linear_rank_one.weight).item())
|
||
|
|
1
|
||
|
|
|
||
|
|
"""
|
||
|
|
parametrization.train(module.training)
|
||
|
|
if is_parametrized(module, tensor_name):
|
||
|
|
# Correctness checks.
|
||
|
|
# If A is the space of tensors with shape and dtype equal to module.weight
|
||
|
|
# we check that parametrization.forward and parametrization.right_inverse are
|
||
|
|
# functions from A to A
|
||
|
|
if not unsafe:
|
||
|
|
Y = getattr(module, tensor_name)
|
||
|
|
X = parametrization(Y)
|
||
|
|
if not isinstance(X, Tensor):
|
||
|
|
raise ValueError(
|
||
|
|
f"A parametrization must return a tensor. Got {type(X).__name__}."
|
||
|
|
)
|
||
|
|
if X.dtype != Y.dtype:
|
||
|
|
raise ValueError(
|
||
|
|
"Registering a parametrization may not change the dtype of the tensor, unless the `unsafe` flag is enabled.\n"
|
||
|
|
f"module.{tensor_name}.dtype: {Y.dtype}\n"
|
||
|
|
f"parametrization(module.{tensor_name}).dtype: {X.dtype}"
|
||
|
|
)
|
||
|
|
if X.shape != Y.shape:
|
||
|
|
raise ValueError(
|
||
|
|
"Registering a parametrization may not change the shape of the tensor, unless the `unsafe` flag is enabled.\n"
|
||
|
|
f"module.{tensor_name}.shape: {Y.shape}\n"
|
||
|
|
f"parametrization(module.{tensor_name}).shape: {X.shape}"
|
||
|
|
)
|
||
|
|
if hasattr(parametrization, "right_inverse"):
|
||
|
|
try:
|
||
|
|
Z = parametrization.right_inverse(X) # type: ignore[operator]
|
||
|
|
except NotImplementedError:
|
||
|
|
pass
|
||
|
|
else:
|
||
|
|
if not isinstance(Z, Tensor):
|
||
|
|
raise ValueError(
|
||
|
|
f"parametrization.right_inverse must return a tensor. Got: {type(Z).__name__}"
|
||
|
|
)
|
||
|
|
if Z.dtype != Y.dtype:
|
||
|
|
raise ValueError(
|
||
|
|
"The tensor returned by parametrization.right_inverse must have the same dtype "
|
||
|
|
f"as module.{tensor_name}, unless the `unsafe` flag is enabled.\n"
|
||
|
|
f"module.{tensor_name}.dtype: {Y.dtype}\n"
|
||
|
|
f"returned dtype: {Z.dtype}"
|
||
|
|
)
|
||
|
|
if Z.shape != Y.shape:
|
||
|
|
raise ValueError(
|
||
|
|
"The tensor returned by parametrization.right_inverse must have the same shape "
|
||
|
|
f"as module.{tensor_name}, unless the `unsafe` flag is enabled.\n"
|
||
|
|
f"module.{tensor_name}.shape: {Y.shape}\n"
|
||
|
|
f"returned shape: {Z.shape}"
|
||
|
|
)
|
||
|
|
# else right_inverse is assumed to be the identity
|
||
|
|
|
||
|
|
# add the new parametrization to the parametrization list
|
||
|
|
assert isinstance(module.parametrizations, ModuleDict) # Make mypy happy
|
||
|
|
module.parametrizations[tensor_name].append(parametrization)
|
||
|
|
# If unsafe was True in previous parametrization, keep it enabled
|
||
|
|
module.parametrizations[tensor_name].unsafe |= unsafe # type: ignore[index, union-attr]
|
||
|
|
elif tensor_name in module._buffers or tensor_name in module._parameters:
|
||
|
|
# Set the parametrization mechanism
|
||
|
|
# Fetch the original buffer or parameter
|
||
|
|
original = getattr(module, tensor_name)
|
||
|
|
# We create this early to check for possible errors
|
||
|
|
parametrizations = ParametrizationList([parametrization], original, unsafe=unsafe)
|
||
|
|
# Delete the previous parameter or buffer
|
||
|
|
delattr(module, tensor_name)
|
||
|
|
# If this is the first parametrization registered on the module,
|
||
|
|
# we prepare the module to inject the property
|
||
|
|
if not is_parametrized(module):
|
||
|
|
# Change the class
|
||
|
|
_inject_new_class(module)
|
||
|
|
# Inject a ``ModuleDict`` into the instance under module.parametrizations
|
||
|
|
module.parametrizations = ModuleDict()
|
||
|
|
# Add a property into the class
|
||
|
|
_inject_property(module, tensor_name)
|
||
|
|
# Add a ParametrizationList
|
||
|
|
assert isinstance(module.parametrizations, ModuleDict) # Make mypy happy
|
||
|
|
module.parametrizations[tensor_name] = parametrizations
|
||
|
|
else:
|
||
|
|
raise ValueError(
|
||
|
|
f"Module '{module}' does not have a parameter, a buffer, or a "
|
||
|
|
f"parametrized element with name '{tensor_name}'"
|
||
|
|
)
|
||
|
|
return module
|
||
|
|
|
||
|
|
|
||
|
|
def is_parametrized(module: Module, tensor_name: Optional[str] = None) -> bool:
|
||
|
|
r"""Determine if a module has a parametrization.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
module (nn.Module): module to query
|
||
|
|
tensor_name (str, optional): name of the parameter in the module
|
||
|
|
Default: ``None``
|
||
|
|
Returns:
|
||
|
|
``True`` if :attr:`module` has a parametrization for the parameter named :attr:`tensor_name`,
|
||
|
|
or if it has any parametrization when :attr:`tensor_name` is ``None``;
|
||
|
|
otherwise ``False``
|
||
|
|
"""
|
||
|
|
parametrizations = getattr(module, "parametrizations", None)
|
||
|
|
if parametrizations is None or not isinstance(parametrizations, ModuleDict):
|
||
|
|
return False
|
||
|
|
if tensor_name is None:
|
||
|
|
# Check that there is at least one parametrized buffer or Parameter
|
||
|
|
return len(parametrizations) > 0
|
||
|
|
else:
|
||
|
|
return tensor_name in parametrizations
|
||
|
|
|
||
|
|
def remove_parametrizations(
|
||
|
|
module: Module, tensor_name: str, leave_parametrized: bool = True
|
||
|
|
) -> Module:
|
||
|
|
r"""Remove the parametrizations on a tensor in a module.
|
||
|
|
|
||
|
|
- If ``leave_parametrized=True``, ``module[tensor_name]`` will be set to
|
||
|
|
its current output. In this case, the parametrization shall not change the ``dtype``
|
||
|
|
of the tensor.
|
||
|
|
- If ``leave_parametrized=False``, ``module[tensor_name]`` will be set to
|
||
|
|
the unparametrised tensor in ``module.parametrizations[tensor_name].original``.
|
||
|
|
This is only possible when the parametrization depends on just one tensor.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
module (nn.Module): module from which remove the parametrization
|
||
|
|
tensor_name (str): name of the parametrization to be removed
|
||
|
|
leave_parametrized (bool, optional): leave the attribute :attr:`tensor_name` parametrized.
|
||
|
|
Default: ``True``
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
Module: module
|
||
|
|
|
||
|
|
Raises:
|
||
|
|
ValueError: if ``module[tensor_name]`` is not parametrized
|
||
|
|
ValueError: if ``leave_parametrized=False`` and the parametrization depends on several tensors
|
||
|
|
"""
|
||
|
|
if not is_parametrized(module, tensor_name):
|
||
|
|
raise ValueError(f"Module {module} does not have a parametrization on {tensor_name}")
|
||
|
|
|
||
|
|
# Fetch the original tensor
|
||
|
|
assert isinstance(module.parametrizations, ModuleDict) # Make mypy happy
|
||
|
|
parametrizations = module.parametrizations[tensor_name]
|
||
|
|
if parametrizations.is_tensor:
|
||
|
|
original = parametrizations.original
|
||
|
|
if leave_parametrized:
|
||
|
|
with torch.no_grad():
|
||
|
|
t = getattr(module, tensor_name)
|
||
|
|
# We know they have the same dtype because we have checked this when registering the
|
||
|
|
# parametrizations. As such, we can use set_
|
||
|
|
# We do this so that the parameter does not to change the id()
|
||
|
|
# This way the user does not need to update the optimizer
|
||
|
|
with torch.no_grad():
|
||
|
|
if type(original) is torch.Tensor:
|
||
|
|
original.set_(t)
|
||
|
|
else:
|
||
|
|
try:
|
||
|
|
original.set_(t)
|
||
|
|
except RuntimeError as e:
|
||
|
|
# TODO: Fix this for tensor subclasses that are parameters:
|
||
|
|
# RuntimeError: set_storage is not allowed on a Tensor created from .data or .detach().
|
||
|
|
raise RuntimeError("Calling remove_parametrizations() with leave_parametrized=True "
|
||
|
|
"for a parameter that is an instance of a tensor subclass requires "
|
||
|
|
"set_() to be implemented correctly for the tensor subclass. Either "
|
||
|
|
"set leave_parametrized=False or provide a working implementation for "
|
||
|
|
"set_() in the tensor subclass.") from e
|
||
|
|
else:
|
||
|
|
if leave_parametrized:
|
||
|
|
# We cannot use no_grad because we need to know whether one or more
|
||
|
|
# original tensors required grad
|
||
|
|
t = getattr(module, tensor_name)
|
||
|
|
# We'll have to trust the user to add it to the optimizer
|
||
|
|
original = Parameter(t) if t.requires_grad else t
|
||
|
|
else:
|
||
|
|
raise ValueError("Cannot leave unparametrized (`leave_parametrized=False`) a tensor "
|
||
|
|
"that is parametrized in terms of a sequence of tensors.")
|
||
|
|
|
||
|
|
# Delete the property that manages the parametrization
|
||
|
|
delattr(module.__class__, tensor_name)
|
||
|
|
# Delete the ParametrizationList
|
||
|
|
del module.parametrizations[tensor_name]
|
||
|
|
|
||
|
|
# Restore the parameter / buffer into the main class
|
||
|
|
_register_parameter_or_buffer(module, tensor_name, original)
|
||
|
|
|
||
|
|
# Roll back the parametrized class if no other buffer or parameter
|
||
|
|
# is currently parametrized in this class
|
||
|
|
if not is_parametrized(module):
|
||
|
|
delattr(module, "parametrizations")
|
||
|
|
# Restore class
|
||
|
|
orig_cls = module.__class__.__bases__[0]
|
||
|
|
module.__class__ = orig_cls
|
||
|
|
return module
|
||
|
|
|
||
|
|
def type_before_parametrizations(module: Module) -> type:
|
||
|
|
r"""Return the module type before parametrizations were applied and if not, then it returns the module type.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
module (nn.Module): module to get type of
|
||
|
|
"""
|
||
|
|
if is_parametrized(module):
|
||
|
|
return module.__class__.__bases__[0]
|
||
|
|
else:
|
||
|
|
return type(module)
|
||
|
|
|
||
|
|
def transfer_parametrizations_and_params(
|
||
|
|
from_module: Module, to_module: Module, tensor_name: Optional[str] = None
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) -> Module:
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r"""Transfer parametrizations and the parameters they parametrize from :attr:`from_module` to :attr:`to_module`.
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|
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If :attr:`tensor_name` is specified, only transfers the specified parameter, otherwise
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|
transfers all parametrized parameters. If those parameters do not exist in to_module, it will create them.
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|
Does nothing if from_module is not parametrized.
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|
|
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||
|
|
Args:
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|
|
from_module (nn.Module): module to transfer from
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|
|
to_module (nn.Module): module to transfer to
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||
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|
tensor_name (str, optional): parameter to transfer
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||
|
|
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||
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|
Returns:
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||
|
|
Module: to_module
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|
"""
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if is_parametrized(from_module):
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assert isinstance(from_module.parametrizations, ModuleDict) # for mypy
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||
|
|
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|
# get list of all params or the single param to transfer
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||
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|
parameters_to_transfer: Union[list, ModuleDict] = (
|
||
|
|
from_module.parametrizations if tensor_name is None else [tensor_name]
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|
|
)
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||
|
|
|
||
|
|
assert hasattr(parameters_to_transfer, "__iter__") # for mypy
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||
|
|
for parameter_name in parameters_to_transfer:
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||
|
|
|
||
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|
# initialize the to-be-transferred param in to_module if it doesn't exist already
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||
|
|
if not hasattr(to_module, parameter_name):
|
||
|
|
setattr(
|
||
|
|
to_module,
|
||
|
|
parameter_name,
|
||
|
|
Parameter(getattr(from_module, parameter_name)),
|
||
|
|
)
|
||
|
|
|
||
|
|
# apply the params's parametrizations to to_module
|
||
|
|
for param_func in from_module.parametrizations[parameter_name]:
|
||
|
|
register_parametrization(to_module, parameter_name, param_func)
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||
|
|
assert isinstance(to_module.parametrizations, ModuleDict) # for mypy
|
||
|
|
|
||
|
|
# make values match, original values can be stored in either original or
|
||
|
|
# original0, original1..., need to check both cases
|
||
|
|
if hasattr(from_module.parametrizations[parameter_name], "original"):
|
||
|
|
to_module.parametrizations[parameter_name].original = \
|
||
|
|
from_module.parametrizations[parameter_name].original
|
||
|
|
else:
|
||
|
|
num = 0
|
||
|
|
orig_num = "original" + str(num)
|
||
|
|
# loop through each original# until all values have been set
|
||
|
|
while hasattr(from_module.parametrizations[parameter_name], orig_num):
|
||
|
|
setattr(
|
||
|
|
to_module.parametrizations[parameter_name],
|
||
|
|
orig_num,
|
||
|
|
getattr(from_module.parametrizations[parameter_name], orig_num),
|
||
|
|
)
|
||
|
|
num = num + 1
|
||
|
|
orig_num = "original" + str(num)
|
||
|
|
|
||
|
|
return to_module
|