##########################################################################
# basf2 (Belle II Analysis Software Framework) #
# Author: The Belle II Collaboration #
# #
# See git log for contributors and copyright holders. #
# This file is licensed under LGPL-3.0, see LICENSE.md. #
##########################################################################
import torch
from torch_geometric.nn import MetaLayer
from .geometric_layers import NodeLayer, EdgeLayer, GlobalLayer
[docs]
class GraFEIModel(torch.nn.Module):
"""
Actual implementation of the model,
based on the
`MetaLayer <https://pytorch-geometric.readthedocs.io/en/latest/generated/torch_geometric.nn.models.MetaLayer.html>`_
class.
.. seealso::
`Relational inductive biases, deep learning, and graph networks <https://arxiv.org/abs/1806.01261>`_
The network is composed of:
1. A first MetaLayer to increase the number of nodes and edges features;
2. A number of intermediate MetaLayers (tunable in config file);
3. A last MetaLayer to decrease the number of node and edge features to the desired output dimension.
.. figure:: figs/graFEI.png
:width: 42em
:align: center
Each MetaLayer is in turn composed of `EdgeLayer`, `NodeLayer` and `GlobalLayer` sub-blocks.
Args:
nfeat_in_dim (int): Node features dimension (number of input node features).
efeat_in_dim (int): Edge features dimension (number of input edge features).
gfeat_in_dim (int): Global features dimension (number of input global features).
edge_classes (int): Edge features output dimension (i.e. number of different edge labels in the LCAS matrix).
x_classes (int): Node features output dimension (i.e. number of different mass hypotheses).
hidden_layer_dim (int): Intermediate features dimension (same for node, edge and global).
num_hid_layers (int): Number of hidden layers in every MetaLayer.
num_ML (int): Number of intermediate MetaLayers.
dropout (float): Dropout rate :math:`r \\in [0,1]`.
global_layer (bool): Whether to use global layer.
:return: Node, edge and global features after model evaluation.
:rtype: tuple(`Tensor <https://pytorch.org/docs/stable/tensors.html#torch.Tensor>`_)
"""
def __init__(
self,
nfeat_in_dim,
efeat_in_dim,
gfeat_in_dim,
edge_classes=6,
x_classes=7,
hidden_layer_dim=128,
num_hid_layers=1,
num_ML=1,
dropout=0.0,
global_layer=True,
**kwargs
):
"""
Initialization.
"""
super(GraFEIModel, self).__init__()
#: First MetaLayer
self.first_ML = MetaLayer(
EdgeLayer(
nfeat_in_dim,
efeat_in_dim,
gfeat_in_dim,
hidden_layer_dim,
hidden_layer_dim,
num_hid_layers,
dropout,
),
NodeLayer(
nfeat_in_dim,
hidden_layer_dim,
gfeat_in_dim,
hidden_layer_dim,
hidden_layer_dim,
num_hid_layers,
dropout,
),
GlobalLayer(
hidden_layer_dim,
hidden_layer_dim,
gfeat_in_dim,
hidden_layer_dim,
hidden_layer_dim,
num_hid_layers,
dropout,
)
if global_layer
else None,
)
#: Intermediate MetaLayers
self.ML_list = torch.nn.ModuleList(
[
MetaLayer(
EdgeLayer(
hidden_layer_dim,
hidden_layer_dim,
hidden_layer_dim if global_layer else 0,
hidden_layer_dim,
hidden_layer_dim,
num_hid_layers,
dropout,
),
NodeLayer(
hidden_layer_dim,
hidden_layer_dim,
hidden_layer_dim if global_layer else 0,
hidden_layer_dim,
hidden_layer_dim,
num_hid_layers,
dropout,
),
GlobalLayer(
hidden_layer_dim,
hidden_layer_dim,
hidden_layer_dim,
hidden_layer_dim,
hidden_layer_dim,
num_hid_layers,
dropout,
)
if global_layer
else None,
)
for _ in range(num_ML)
]
)
#: Output MetaLayer
self.last_ML = MetaLayer(
EdgeLayer(
hidden_layer_dim,
hidden_layer_dim,
hidden_layer_dim if global_layer else 0,
hidden_layer_dim,
edge_classes,
num_hid_layers,
dropout,
normalize=False, # Do not normalize output layer
),
NodeLayer(
hidden_layer_dim,
edge_classes,
hidden_layer_dim if global_layer else 0,
hidden_layer_dim,
x_classes,
num_hid_layers,
dropout,
normalize=False, # Do not normalize output layer
),
GlobalLayer(
x_classes,
edge_classes,
hidden_layer_dim,
hidden_layer_dim,
1,
num_hid_layers,
dropout,
normalize=False, # Do not normalize output layer
)
if global_layer
else None,
)
def forward(self, batch):
"""
Called internally by PyTorch to propagate the input through the network.
"""
x, u, edge_index, edge_attr, torch_batch = (
batch.x,
batch.u,
batch.edge_index,
batch.edge_attr,
batch.batch,
)
x, edge_attr, u = self.first_ML(
x=x, edge_index=edge_index, edge_attr=edge_attr, u=u, batch=torch_batch
)
del batch
for ML in self.ML_list:
x_skip = x
edge_skip = edge_attr
u_skip = u
x, edge_attr, u = ML(
x=x, edge_index=edge_index, edge_attr=edge_attr, u=u, batch=torch_batch
)
# Skip connections are added
x += x_skip
edge_attr += edge_skip
u += u_skip
del x_skip, edge_skip, u_skip
x, edge_attr, u = self.last_ML(
x=x, edge_index=edge_index, edge_attr=edge_attr, u=u, batch=torch_batch
)
# Edge labels are symmetrized
edge_index_t = edge_index[[1, 0]] # edge_index transposed
for i in range(edge_attr.shape[1]):
# edge_attr converted to sparse tensor...
edge_matrix = torch.sparse_coo_tensor(
edge_index, edge_attr[:, i]
)
# ... and its transposed
edge_matrix_t = torch.sparse_coo_tensor(
edge_index_t, edge_attr[:, i]
)
# Symmetrization happens here
edge_attr[:, i] = (
((edge_matrix + edge_matrix_t) / 2.0).coalesce()
).values()
return x, edge_attr, u
