Files
PINA/pina/label_tensor.py
2025-03-19 17:46:34 +01:00

454 lines
16 KiB
Python

""" Module for LabelTensor """
from copy import deepcopy, copy
import torch
from torch import Tensor
def issubset(a, b):
"""
Check if a is a subset of b.
"""
return set(a).issubset(set(b))
class LabelTensor(torch.Tensor):
"""Torch tensor with a label for any column."""
@staticmethod
def __new__(cls, x, labels, *args, **kwargs):
return super().__new__(cls, x, *args, **kwargs)
@property
def tensor(self):
return self.as_subclass(Tensor)
def __init__(self, x, labels):
"""
Construct a `LabelTensor` by passing a dict of the labels
:Example:
>>> from pina import LabelTensor
>>> tensor = LabelTensor(
>>> torch.rand((2000, 3)),
{1: {"name": "space"['a', 'b', 'c'])
"""
self.dim_names = None
self.labels = labels
@property
def labels(self):
"""Property decorator for labels
:return: labels of self
:rtype: list
"""
return self._labels[self.tensor.ndim - 1]['dof']
@property
def full_labels(self):
"""Property decorator for labels
:return: labels of self
:rtype: list
"""
return self._labels
@labels.setter
def labels(self, labels):
""""
Set properly the parameter _labels
:param labels: Labels to assign to the class variable _labels.
:type: labels: str | list(str) | dict
"""
if hasattr(self, 'labels') is False:
self.init_labels()
if isinstance(labels, dict):
self.update_labels_from_dict(labels)
elif isinstance(labels, list):
self.update_labels_from_list(labels)
elif isinstance(labels, str):
labels = [labels]
self.update_labels_from_list(labels)
else:
raise ValueError("labels must be list, dict or string.")
self.set_names()
def set_names(self):
labels = self.full_labels
self.dim_names = {}
for dim in range(self.tensor.ndim):
self.dim_names[labels[dim]['name']] = dim
def extract(self, label_to_extract):
"""
Extract the subset of the original tensor by returning all the columns
corresponding to the passed ``label_to_extract``.
:param label_to_extract: The label(s) to extract.
:type label_to_extract: str | list(str) | tuple(str)
:raises TypeError: Labels are not ``str``.
:raises ValueError: Label to extract is not in the labels ``list``.
"""
if isinstance(label_to_extract, (str, int)):
label_to_extract = [label_to_extract]
if isinstance(label_to_extract, (tuple, list)):
return self._extract_from_list(label_to_extract)
if isinstance(label_to_extract, dict):
return self._extract_from_dict(label_to_extract)
raise ValueError('labels_to_extract must be str or list or dict')
def _extract_from_list(self, labels_to_extract):
# Store locally all necessary obj/variables
ndim = self.tensor.ndim
labels = self.full_labels
tensor = self.tensor
last_dim_label = self.labels
# Verify if all the labels in labels_to_extract are in last dimension
if set(labels_to_extract).issubset(last_dim_label) is False:
raise ValueError(
'Cannot extract a dof which is not in the original LabelTensor')
# Extract index to extract
idx_to_extract = [last_dim_label.index(i) for i in labels_to_extract]
# Perform extraction
new_tensor = tensor[..., idx_to_extract]
# Manage labels
new_labels = copy(labels)
last_dim_new_label = {ndim - 1: {
'dof': list(labels_to_extract),
'name': labels[ndim - 1]['name']
}}
new_labels.update(last_dim_new_label)
return LabelTensor(new_tensor, new_labels)
def _extract_from_dict(self, labels_to_extract):
labels = self.full_labels
tensor = self.tensor
ndim = tensor.ndim
new_labels = deepcopy(labels)
new_tensor = tensor
for k, _ in labels_to_extract.items():
idx_dim = self.dim_names[k]
dim_labels = labels[idx_dim]['dof']
if isinstance(labels_to_extract[k], (int, str)):
labels_to_extract[k] = [labels_to_extract[k]]
if set(labels_to_extract[k]).issubset(dim_labels) is False:
raise ValueError(
'Cannot extract a dof which is not in the original '
'LabelTensor')
idx_to_extract = [dim_labels.index(i) for i in labels_to_extract[k]]
indexer = [slice(None)] * idx_dim + [idx_to_extract] + [
slice(None)] * (ndim - idx_dim - 1)
new_tensor = new_tensor[indexer]
dim_new_label = {idx_dim: {
'dof': labels_to_extract[k],
'name': labels[idx_dim]['name']
}}
new_labels.update(dim_new_label)
return LabelTensor(new_tensor, new_labels)
def __str__(self):
"""
returns a string with the representation of the class
"""
s = ''
for key, value in self._labels.items():
s += f"{key}: {value}\n"
s += '\n'
s += super().__str__()
return s
@staticmethod
def cat(tensors, dim=0):
"""
Stack a list of tensors. For example, given a tensor `a` of shape
`(n,m,dof)` and a tensor `b` of dimension `(n',m,dof)`
the resulting tensor is of shape `(n+n',m,dof)`
:param tensors: tensors to concatenate
:type tensors: list(LabelTensor)
:param dim: dimensions on which you want to perform the operation (default 0)
:type dim: int
:rtype: LabelTensor
:raises ValueError: either number dof or dimensions names differ
"""
if len(tensors) == 0:
return []
if len(tensors) == 1:
return tensors[0]
new_labels_cat_dim = LabelTensor._check_validity_before_cat(tensors,
dim)
# Perform cat on tensors
new_tensor = torch.cat(tensors, dim=dim)
# Update labels
labels = tensors[0].full_labels
labels.pop(dim)
new_labels_cat_dim = new_labels_cat_dim if len(
set(new_labels_cat_dim)) == len(new_labels_cat_dim) \
else range(new_tensor.shape[dim])
labels[dim] = {'dof': new_labels_cat_dim,
'name': tensors[1].full_labels[dim]['name']}
return LabelTensor(new_tensor, labels)
@staticmethod
def _check_validity_before_cat(tensors, dim):
n_dims = tensors[0].ndim
new_labels_cat_dim = []
# Check if names and dof of the labels are the same in all dimensions
# except in dim
for i in range(n_dims):
name = tensors[0].full_labels[i]['name']
if i != dim:
dof = tensors[0].full_labels[i]['dof']
for tensor in tensors:
dof_to_check = tensor.full_labels[i]['dof']
name_to_check = tensor.full_labels[i]['name']
if dof != dof_to_check or name != name_to_check:
raise ValueError(
'dimensions must have the same dof and name')
else:
for tensor in tensors:
new_labels_cat_dim += tensor.full_labels[i]['dof']
name_to_check = tensor.full_labels[i]['name']
if name != name_to_check:
raise ValueError(
'Dimensions to concatenate must have the same name')
return new_labels_cat_dim
def requires_grad_(self, mode=True):
lt = super().requires_grad_(mode)
lt.labels = self._labels
return lt
@property
def dtype(self):
return super().dtype
def to(self, *args, **kwargs):
"""
Performs Tensor dtype and/or device conversion. For more details, see
:meth:`torch.Tensor.to`.
"""
tmp = super().to(*args, **kwargs)
new = self.__class__.clone(self)
new.data = tmp.data
return new
def clone(self, *args, **kwargs):
"""
Clone the LabelTensor. For more details, see
:meth:`torch.Tensor.clone`.
:return: A copy of the tensor.
:rtype: LabelTensor
"""
out = LabelTensor(super().clone(*args, **kwargs), self._labels)
return out
def init_labels(self):
self._labels = {
idx_: {
'dof': range(self.tensor.shape[idx_]),
'name': idx_
} for idx_ in range(self.tensor.ndim)
}
def update_labels_from_dict(self, labels):
"""
Update the internal label representation according to the values passed
as input.
:param labels: The label(s) to update.
:type labels: dict
:raises ValueError: dof list contain duplicates or number of dof does
not match with tensor shape
"""
tensor_shape = self.tensor.shape
# Check dimensionality
for k, v in labels.items():
if len(v['dof']) != len(set(v['dof'])):
raise ValueError("dof must be unique")
if len(v['dof']) != tensor_shape[k]:
raise ValueError(
'Number of dof does not match with tensor dimension')
# Perform update
self._labels.update(labels)
def update_labels_from_list(self, labels):
"""
Given a list of dof, this method update the internal label
representation
:param labels: The label(s) to update.
:type labels: list
"""
# Create a dict with labels
last_dim_labels = {
self.tensor.ndim - 1: {'dof': labels, 'name': self.tensor.ndim - 1}}
self.update_labels_from_dict(last_dim_labels)
@staticmethod
def summation(tensors):
if len(tensors) == 0:
raise ValueError('tensors list must not be empty')
if len(tensors) == 1:
return tensors[0]
# Collect all labels
labels = tensors[0].full_labels
# Check labels of all the tensors in each dimension
for j in range(tensors[0].ndim):
for i in range(1, len(tensors)):
if labels[j] != tensors[i].full_labels[j]:
labels.pop(j)
break
# Sum tensors
data = torch.zeros(tensors[0].tensor.shape)
for tensor in tensors:
data += tensor.tensor
new_tensor = LabelTensor(data, labels)
return new_tensor
def append(self, tensor, mode='std'):
if mode == 'std':
# Call cat on last dimension
new_label_tensor = LabelTensor.cat([self, tensor],
dim=self.tensor.ndim - 1)
elif mode == 'cross':
# Crete tensor and call cat on last dimension
tensor1 = self
tensor2 = tensor
n1 = tensor1.shape[0]
n2 = tensor2.shape[0]
tensor1 = LabelTensor(tensor1.repeat(n2, 1), labels=tensor1.labels)
tensor2 = LabelTensor(tensor2.repeat_interleave(n1, dim=0),
labels=tensor2.labels)
new_label_tensor = LabelTensor.cat([tensor1, tensor2],
dim=self.tensor.ndim - 1)
else:
raise ValueError('mode must be either "std" or "cross"')
return new_label_tensor
@staticmethod
def vstack(label_tensors):
"""
Stack tensors vertically. For more details, see
:meth:`torch.vstack`.
:param list(LabelTensor) label_tensors: the tensors to stack. They need
to have equal labels.
:return: the stacked tensor
:rtype: LabelTensor
"""
return LabelTensor.cat(label_tensors, dim=0)
def __getitem__(self, index):
"""
TODO: Complete docstring
:param index:
:return:
"""
if isinstance(index, str) or (isinstance(index, (tuple, list)) and all(
isinstance(a, str) for a in index)):
return self.extract(index)
selected_lt = super().__getitem__(index)
if isinstance(index, (int, slice)):
return self._getitem_int_slice(index, selected_lt)
if len(index) == self.tensor.ndim:
return self._getitem_full_dim_indexing(index, selected_lt)
if isinstance(index, torch.Tensor) or (
isinstance(index, (tuple, list)) and all(
isinstance(x, int) for x in index)):
return self._getitem_permutation(index, selected_lt)
raise ValueError('Not recognized index type')
def _getitem_int_slice(self, index, selected_lt):
"""
:param index:
:param selected_lt:
:return:
"""
if selected_lt.ndim == 1:
selected_lt = selected_lt.reshape(1, -1)
if hasattr(self, "labels"):
new_labels = deepcopy(self.full_labels)
to_update_dof = new_labels[0]['dof'][index]
to_update_dof = to_update_dof if isinstance(to_update_dof, (
tuple, list, range)) else [to_update_dof]
new_labels.update(
{0: {'dof': to_update_dof, 'name': new_labels[0]['name']}}
)
selected_lt.labels = new_labels
return selected_lt
def _getitem_full_dim_indexing(self, index, selected_lt):
new_labels = {}
old_labels = self.full_labels
if selected_lt.ndim == 1:
selected_lt = selected_lt.reshape(-1, 1)
new_labels = deepcopy(old_labels)
new_labels[1].update({'dof': old_labels[1]['dof'][index[1]],
'name': old_labels[1]['name']})
idx = 0
for j in range(selected_lt.ndim):
if not isinstance(index[j], int):
if hasattr(self, "labels"):
new_labels.update(
self._update_label_for_dim(old_labels, index[j], idx))
idx += 1
selected_lt.labels = new_labels
return selected_lt
def _getitem_permutation(self, index, selected_lt):
new_labels = deepcopy(self.full_labels)
new_labels.update(self._update_label_for_dim(self.full_labels, index,
0))
selected_lt.labels = self.labels
return selected_lt
@staticmethod
def _update_label_for_dim(old_labels, index, dim):
"""
TODO
:param old_labels:
:param index:
:param dim:
:return:
"""
if isinstance(index, torch.Tensor):
index = index.nonzero()
if isinstance(index, list):
return {dim: {'dof': [old_labels[dim]['dof'][i] for i in index],
'name': old_labels[dim]['name']}}
else:
return {dim: {'dof': old_labels[dim]['dof'][index],
'name': old_labels[dim]['name']}}
def sort_labels(self, dim=None):
def argsort(lst):
return sorted(range(len(lst)), key=lambda x: lst[x])
if dim is None:
dim = self.tensor.ndim - 1
labels = self.full_labels[dim]['dof']
sorted_index = argsort(labels)
indexer = [slice(None)] * self.tensor.ndim
indexer[dim] = sorted_index
new_labels = deepcopy(self.full_labels)
new_labels[dim] = {'dof': sorted(labels),
'name': new_labels[dim]['name']}
return LabelTensor(self.tensor[indexer], new_labels)