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# Copyright 2021 AlQuraishi Laboratory | |
# | |
# Licensed under the Apache License, Version 2.0 (the "License"); | |
# you may not use this file except in compliance with the License. | |
# You may obtain a copy of the License at | |
# | |
# http://www.apache.org/licenses/LICENSE-2.0 | |
# | |
# Unless required by applicable law or agreed to in writing, software | |
# distributed under the License is distributed on an "AS IS" BASIS, | |
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
# See the License for the specific language governing permissions and | |
# limitations under the License. | |
from Bio.SVDSuperimposer import SVDSuperimposer | |
import numpy as np | |
import torch | |
def _superimpose_np(reference, coords): | |
""" | |
Superimposes coordinates onto a reference by minimizing RMSD using SVD. | |
Args: | |
reference: | |
[N, 3] reference array | |
coords: | |
[N, 3] array | |
Returns: | |
A tuple of [N, 3] superimposed coords and the final RMSD. | |
""" | |
sup = SVDSuperimposer() | |
sup.set(reference, coords) | |
sup.run() | |
rotran = sup.get_rotran() | |
return sup.get_transformed(), sup.get_rms(), rotran | |
def _superimpose_single(reference, coords): | |
reference_np = reference.detach().cpu().numpy() | |
coords_np = coords.detach().cpu().numpy() | |
superimposed, rmsd, rotran = _superimpose_np(reference_np, coords_np) | |
rotran = (coords.new_tensor(rotran[0]), coords.new_tensor(rotran[1])) | |
return coords.new_tensor(superimposed), coords.new_tensor(rmsd), rotran | |
def superimpose(reference, coords, mask): | |
""" | |
Superimposes coordinates onto a reference by minimizing RMSD using SVD. | |
Args: | |
reference: | |
[*, N, 3] reference tensor | |
coords: | |
[*, N, 3] tensor | |
mask: | |
[*, N] tensor | |
Returns: | |
A tuple of [*, N, 3] superimposed coords and [*] final RMSDs. | |
""" | |
def select_unmasked_coords(coords, mask): | |
return torch.masked_select( | |
coords, | |
(mask > 0.)[..., None], | |
).reshape(-1, 3) | |
batch_dims = reference.shape[:-2] | |
flat_reference = reference.reshape((-1,) + reference.shape[-2:]) | |
flat_coords = coords.reshape((-1,) + reference.shape[-2:]) | |
flat_mask = mask.reshape((-1,) + mask.shape[-1:]) | |
superimposed_list = [] | |
rmsds = [] | |
rotrans = [] | |
for r, c, m in zip(flat_reference, flat_coords, flat_mask): | |
r_unmasked_coords = select_unmasked_coords(r, m) | |
c_unmasked_coords = select_unmasked_coords(c, m) | |
superimposed, rmsd, rotran = _superimpose_single( | |
r_unmasked_coords, | |
c_unmasked_coords | |
) | |
# This is very inelegant, but idk how else to invert the masking | |
# procedure. | |
count = 0 | |
superimposed_full_size = torch.zeros_like(r) | |
for i, unmasked in enumerate(m): | |
if(unmasked): | |
superimposed_full_size[i] = superimposed[count] | |
count += 1 | |
superimposed_list.append(superimposed_full_size) | |
rmsds.append(rmsd) | |
rotrans.append(rotran) | |
superimposed_stacked = torch.stack(superimposed_list, dim=0) | |
rmsds_stacked = torch.stack(rmsds, dim=0) | |
rots = [r for r, t in rotrans] | |
rots_stacked = torch.stack(rots, dim=0) | |
trans = [t for r, t in rotrans] | |
trans_stacked = torch.stack(trans, dim=0) | |
superimposed_reshaped = superimposed_stacked.reshape( | |
batch_dims + coords.shape[-2:] | |
) | |
rmsds_reshaped = rmsds_stacked.reshape( | |
batch_dims | |
) | |
return superimposed_reshaped, rmsds_reshaped, rots_stacked, trans_stacked | |