前往小程序,Get更优阅读体验!
立即前往
首页
学习
活动
专区
工具
TVP
发布
社区首页 >专栏 >DGL & RDKit | 基于Attentive FP的分子性质线性模型

DGL & RDKit | 基于Attentive FP的分子性质线性模型

作者头像
DrugAI
发布2021-02-01 10:49:13
2K0
发布2021-02-01 10:49:13
举报
文章被收录于专栏:DrugAI

基于分子图的深度学习在化学和药物领域非常热门。

2019年8月13日JMC(Journal of Medicinal Chemistry)刊登了一篇文章“Pushing the Boundaries of Molecular Representation for Drug Discovery with the Graph Attention Mechanism”,介绍了一种基于注意力机制的图神经网络模型(Attentive FP)。该模型可以用于分子表征,在多个药物发现相关的数据集上的预测表现达到当前最优,并且该模型所学到的内容具有可解释性。

Attentive FP总体框架以及与同类的图神经网络模型比较

DGL具有许多用于化学信息学、药物与生物信息学任务的函数。

DGL开发人员提供了基于DGL实现的Attentive FP模型, 基于Attentive FP探索分子性质预测的线性模型。

基于Attentive FP的分子性质线性模型

环境准备

  • PyTorch:深度学习框架
  • DGL:基于PyTorch的库,支持深度学习以处理图形
  • RDKit:用于构建分子图并从字符串表示形式绘制结构式
  • MDTraj:用于分子动力学轨迹分析的开源库

导入库

代码语言:javascript
复制
%matplotlib inline 
import matplotlib.pyplot as plt
import os
from rdkit import Chem
from rdkit import RDPaths

import dgl
import numpy as np
import random
import torch
import torch.nn as nn
import torch.nn.functional as F
from torch.utils.data import DataLoader
from torch.utils.data import Dataset
from dgl import model_zoo

from dgl.data.chem.utils import mol_to_complete_graph, mol_to_bigraph

from dgl.data.chem.utils import atom_type_one_hot
from dgl.data.chem.utils import atom_degree_one_hot
from dgl.data.chem.utils import atom_formal_charge
from dgl.data.chem.utils import atom_num_radical_electrons
from dgl.data.chem.utils import atom_hybridization_one_hot
from dgl.data.chem.utils import atom_total_num_H_one_hot
from dgl.data.chem.utils import one_hot_encoding
from dgl.data.chem import CanonicalAtomFeaturizer
from dgl.data.chem import CanonicalBondFeaturizer
from dgl.data.chem import ConcatFeaturizer
from dgl.data.chem import BaseAtomFeaturizer
from dgl.data.chem import BaseBondFeaturizer

from dgl.data.chem import one_hot_encoding
from dgl.data.utils import split_dataset

from functools import partial
from sklearn.metrics import roc_auc_score

定义辅助函数

代码来源于dgl/example。

代码语言:javascript
复制
def chirality(atom):
    try:
        return one_hot_encoding(atom.GetProp('_CIPCode'), ['R', 'S']) + \
               [atom.HasProp('_ChiralityPossible')]
    except:
        return [False, False] + [atom.HasProp('_ChiralityPossible')]

def collate_molgraphs(data):
    """Batching a list of datapoints for dataloader.
    Parameters
    ----------
    data : list of 3-tuples or 4-tuples.
        Each tuple is for a single datapoint, consisting of
        a SMILES, a DGLGraph, all-task labels and optionally
        a binary mask indicating the existence of labels.
    Returns
    -------
    smiles : list
        List of smiles
    bg : BatchedDGLGraph
        Batched DGLGraphs
    labels : Tensor of dtype float32 and shape (B, T)
        Batched datapoint labels. B is len(data) and
        T is the number of total tasks.
    masks : Tensor of dtype float32 and shape (B, T)
        Batched datapoint binary mask, indicating the
        existence of labels. If binary masks are not
        provided, return a tensor with ones.
    """
    assert len(data[0]) in [3, 4], \
        'Expect the tuple to be of length 3 or 4, got {:d}'.format(len(data[0]))
    if len(data[0]) == 3:
        smiles, graphs, labels = map(list, zip(*data))
        masks = None
    else:
        smiles, graphs, labels, masks = map(list, zip(*data))

    bg = dgl.batch(graphs)
    bg.set_n_initializer(dgl.init.zero_initializer)
    bg.set_e_initializer(dgl.init.zero_initializer)
    labels = torch.stack(labels, dim=0)

    if masks is None:
        masks = torch.ones(labels.shape)
    else:
        masks = torch.stack(masks, dim=0)
    return smiles, bg, labels, masks


def run_a_train_epoch(n_epochs, epoch, model, data_loader,loss_criterion, optimizer):
    model.train()
    total_loss = 0
    losses = []

    for batch_id, batch_data in enumerate(data_loader):
        batch_data
        smiles, bg, labels, masks = batch_data
        if torch.cuda.is_available():
            bg.to(torch.device('cuda:0'))
            labels = labels.to('cuda:0')
            masks = masks.to('cuda:0')

        prediction = model(bg, bg.ndata['hv'], bg.edata['he'])
        loss = (loss_criterion(prediction, labels)*(masks != 0).float()).mean()
        #loss = loss_criterion(prediction, labels)
        #print(loss.shape)
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()

        losses.append(loss.data.item())


    total_score = np.mean(losses)
    print('epoch {:d}/{:d}, training {:.4f}'.format( epoch + 1, n_epochs,  total_score))
    return total_score

原子和键特征化器。

代码语言:javascript
复制
atom_featurizer = BaseAtomFeaturizer(
                 {'hv': ConcatFeaturizer([
                  partial(atom_type_one_hot, allowable_set=[
                          'B', 'C', 'N', 'O', 'F', 'Si', 'P', 'S', 'Cl', 'As', 'Se', 'Br', 'Te', 'I', 'At'],
                    encode_unknown=True),
                  partial(atom_degree_one_hot, allowable_set=list(range(6))),
                  atom_formal_charge, atom_num_radical_electrons,
                  partial(atom_hybridization_one_hot, encode_unknown=True),
                  lambda atom: [0], # A placeholder for aromatic information,
                    atom_total_num_H_one_hot, chirality
                 ],
                )})
bond_featurizer = BaseBondFeaturizer({
                                     'he': lambda bond: [0 for _ in range(10)]
    })

加载数据集,rdkit mol对象转换为图对象

带有featurizer的mol_to_bigraph方法将rdkit mol对象转换为图对象。此外,smiles_to_bigraph方法可以将smiles转换为图。

代码语言:javascript
复制
train_mols = Chem.SDMolSupplier('solubility.train.sdf')
train_smi =[Chem.MolToSmiles(m) for m in train_mols]
train_sol = torch.tensor([float(mol.GetProp('SOL')) for mol in train_mols]).reshape(-1,1)
 
test_mols =  Chem.SDMolSupplier('solubility.test.sdf')
test_smi = [Chem.MolToSmiles(m) for m in test_mols]
test_sol = torch.tensor([float(mol.GetProp('SOL')) for mol in test_mols]).reshape(-1,1)
 
 
train_graph =[mol_to_bigraph(mol,
                           node_featurizer=atom_featurizer, 
                           edge_featurizer=bond_featurizer) for mol in train_mols]
 
test_graph =[mol_to_bigraph(mol,
                           node_featurizer=atom_featurizer, 
                           edge_featurizer=bond_featurizer) for mol in test_mols]

AttentivFp模型由model_zoo提供

并定义用于训练和测试的数据加载器。

代码语言:javascript
复制
model = model_zoo.chem.AttentiveFP(node_feat_size=39,
                                  edge_feat_size=10,
                                  num_layers=2,
                                  num_timesteps=2,
                                  graph_feat_size=200,
                                  output_size=1,
                                  dropout=0.2)
 
train_loader = DataLoader(dataset=list(zip(train_smi, train_graph, train_sol)), batch_size=128, collate_fn=collate_molgraphs)
test_loader = DataLoader(dataset=list(zip(test_smi, test_graph, test_sol)), batch_size=128, collate_fn=collate_molgraphs)

学习过程

代码语言:javascript
复制
loss_fn = nn.MSELoss(reduction='none')
optimizer = torch.optim.Adam(model.parameters(), lr=10 ** (-2.5), weight_decay=10 ** (-5.0),)
n_epochs = 100
epochs = []
scores = []
for e in range(n_epochs):
    score = run_a_train_epoch(n_epochs, e, model, train_loader, loss_fn, optimizer)
    epochs.append(e)
    scores.append(score)
 
plt.plot(epochs, scores)

评估模型

代码语言:javascript
复制
from sklearn.metrics import r2_score
print(r2_score(test_sol, res))

0.8938017329965617

本文参与 腾讯云自媒体同步曝光计划,分享自微信公众号。
原始发表:2020-05-10,如有侵权请联系 cloudcommunity@tencent.com 删除

本文分享自 DrugAI 微信公众号,前往查看

如有侵权,请联系 cloudcommunity@tencent.com 删除。

本文参与 腾讯云自媒体同步曝光计划  ,欢迎热爱写作的你一起参与!

评论
登录后参与评论
0 条评论
热度
最新
推荐阅读
目录
  • 基于Attentive FP的分子性质线性模型
    • 环境准备
    领券
    问题归档专栏文章快讯文章归档关键词归档开发者手册归档开发者手册 Section 归档