Files
2026-07-13 13:35:51 +08:00

111 lines
3.8 KiB
Python

import dgl.function as fn
import torch
import torch.nn as nn
from modules.initializers import GlorotOrthogonal
from modules.residual_layer import ResidualLayer
class InteractionBlock(nn.Module):
def __init__(
self,
emb_size,
num_radial,
num_spherical,
num_bilinear,
num_before_skip,
num_after_skip,
activation=None,
):
super(InteractionBlock, self).__init__()
self.activation = activation
# Transformations of Bessel and spherical basis representations
self.dense_rbf = nn.Linear(num_radial, emb_size, bias=False)
self.dense_sbf = nn.Linear(
num_radial * num_spherical, num_bilinear, bias=False
)
# Dense transformations of input messages
self.dense_ji = nn.Linear(emb_size, emb_size)
self.dense_kj = nn.Linear(emb_size, emb_size)
# Bilinear layer
bilin_initializer = torch.empty(
(emb_size, num_bilinear, emb_size)
).normal_(mean=0, std=2 / emb_size)
self.W_bilin = nn.Parameter(bilin_initializer)
# Residual layers before skip connection
self.layers_before_skip = nn.ModuleList(
[
ResidualLayer(emb_size, activation=activation)
for _ in range(num_before_skip)
]
)
self.final_before_skip = nn.Linear(emb_size, emb_size)
# Residual layers after skip connection
self.layers_after_skip = nn.ModuleList(
[
ResidualLayer(emb_size, activation=activation)
for _ in range(num_after_skip)
]
)
self.reset_params()
def reset_params(self):
GlorotOrthogonal(self.dense_rbf.weight)
GlorotOrthogonal(self.dense_sbf.weight)
GlorotOrthogonal(self.dense_ji.weight)
GlorotOrthogonal(self.dense_kj.weight)
GlorotOrthogonal(self.final_before_skip.weight)
def edge_transfer(self, edges):
# Transform from Bessel basis to dence vector
rbf = self.dense_rbf(edges.data["rbf"])
# Initial transformation
x_ji = self.dense_ji(edges.data["m"])
x_kj = self.dense_kj(edges.data["m"])
if self.activation is not None:
x_ji = self.activation(x_ji)
x_kj = self.activation(x_kj)
# w: W * e_RBF \bigodot \sigma(W * m + b)
return {"x_kj": x_kj * rbf, "x_ji": x_ji}
def msg_func(self, edges):
sbf = self.dense_sbf(edges.data["sbf"])
# Apply bilinear layer to interactions and basis function activation
# [None, 8] * [128, 8, 128] * [None, 128] -> [None, 128]
x_kj = torch.einsum(
"wj,wl,ijl->wi", sbf, edges.src["x_kj"], self.W_bilin
)
return {"x_kj": x_kj}
def forward(self, g, l_g):
g.apply_edges(self.edge_transfer)
# nodes correspond to edges and edges correspond to nodes in the original graphs
# node: d, rbf, o, rbf_env, x_kj, x_ji
for k, v in g.edata.items():
l_g.ndata[k] = v
l_g.update_all(self.msg_func, fn.sum("x_kj", "m_update"))
for k, v in l_g.ndata.items():
g.edata[k] = v
# Transformations before skip connection
g.edata["m_update"] = g.edata["m_update"] + g.edata["x_ji"]
for layer in self.layers_before_skip:
g.edata["m_update"] = layer(g.edata["m_update"])
g.edata["m_update"] = self.final_before_skip(g.edata["m_update"])
if self.activation is not None:
g.edata["m_update"] = self.activation(g.edata["m_update"])
# Skip connection
g.edata["m"] = g.edata["m"] + g.edata["m_update"]
# Transformations after skip connection
for layer in self.layers_after_skip:
g.edata["m"] = layer(g.edata["m"])
return g