diffdock / utils /torsion.py
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import networkx as nx
import numpy as np
import torch, copy
from scipy.spatial.transform import Rotation as R
from torch_geometric.utils import to_networkx
from torch_geometric.data import Data
"""
Preprocessing and computation for torsional updates to conformers
"""
def get_transformation_mask(pyg_data):
G = to_networkx(pyg_data.to_homogeneous(), to_undirected=False)
to_rotate = []
edges = pyg_data['ligand', 'ligand'].edge_index.T.numpy()
for i in range(0, edges.shape[0], 2):
assert edges[i, 0] == edges[i+1, 1]
G2 = G.to_undirected()
G2.remove_edge(*edges[i])
if not nx.is_connected(G2):
l = list(sorted(nx.connected_components(G2), key=len)[0])
if len(l) > 1:
if edges[i, 0] in l:
to_rotate.append([])
to_rotate.append(l)
else:
to_rotate.append(l)
to_rotate.append([])
continue
to_rotate.append([])
to_rotate.append([])
mask_edges = np.asarray([0 if len(l) == 0 else 1 for l in to_rotate], dtype=bool)
mask_rotate = np.zeros((np.sum(mask_edges), len(G.nodes())), dtype=bool)
idx = 0
for i in range(len(G.edges())):
if mask_edges[i]:
mask_rotate[idx][np.asarray(to_rotate[i], dtype=int)] = True
idx += 1
return mask_edges, mask_rotate
def modify_conformer_torsion_angles(pos, edge_index, mask_rotate, torsion_updates, as_numpy=False):
pos = copy.deepcopy(pos)
if type(pos) != np.ndarray: pos = pos.cpu().numpy()
for idx_edge, e in enumerate(edge_index.cpu().numpy()):
if torsion_updates[idx_edge] == 0:
continue
u, v = e[0], e[1]
# check if need to reverse the edge, v should be connected to the part that gets rotated
assert not mask_rotate[idx_edge, u]
assert mask_rotate[idx_edge, v]
rot_vec = pos[u] - pos[v] # convention: positive rotation if pointing inwards
rot_vec = rot_vec * torsion_updates[idx_edge] / np.linalg.norm(rot_vec) # idx_edge!
rot_mat = R.from_rotvec(rot_vec).as_matrix()
pos[mask_rotate[idx_edge]] = (pos[mask_rotate[idx_edge]] - pos[v]) @ rot_mat.T + pos[v]
if not as_numpy: pos = torch.from_numpy(pos.astype(np.float32))
return pos
def perturb_batch(data, torsion_updates, split=False, return_updates=False):
if type(data) is Data:
return modify_conformer_torsion_angles(data.pos,
data.edge_index.T[data.edge_mask],
data.mask_rotate, torsion_updates)
pos_new = [] if split else copy.deepcopy(data.pos)
edges_of_interest = data.edge_index.T[data.edge_mask]
idx_node = 0
idx_edges = 0
torsion_update_list = []
for i, mask_rotate in enumerate(data.mask_rotate):
pos = data.pos[idx_node:idx_node + mask_rotate.shape[1]]
edges = edges_of_interest[idx_edges:idx_edges + mask_rotate.shape[0]] - idx_node
torsion_update = torsion_updates[idx_edges:idx_edges + mask_rotate.shape[0]]
torsion_update_list.append(torsion_update)
pos_new_ = modify_conformer_torsion_angles(pos, edges, mask_rotate, torsion_update)
if split:
pos_new.append(pos_new_)
else:
pos_new[idx_node:idx_node + mask_rotate.shape[1]] = pos_new_
idx_node += mask_rotate.shape[1]
idx_edges += mask_rotate.shape[0]
if return_updates:
return pos_new, torsion_update_list
return pos_new