在利用深度学习模型分析DNA序列时,需要对DNA序列进行one hot encoding。以下是使用PyTorch对DNA序列进行One-hot编码的三种方法,并整合在一个代码中,同时计算不同方法处理128条DNA序列的时间消耗:
- import time
- import torch
- import torch.nn.functional as F
- import numpy as np
- # 定义字母与索引的映射关系
- mapping = {'A': 0, 'T': 1, 'C': 2, 'G': 3}
- # 定义DNA序列列表
- sequences = ['ATCG' * 250] * 128 # DNA序列长度为1000bp,共128条序列
- # 方法一:torch.nn.functional.one_hot函数
- start_time = time.time()
- onehot_sequences1 = []
- for sequence in sequences:
- index_sequence = [mapping[base] for base in sequence]
- onehot_sequence = F.one_hot(torch.tensor(index_sequence), num_classes=4).float()
- onehot_sequences1.append(onehot_sequence)
- end_time = time.time()
- method1_time = end_time - start_time
- # 方法二:torch.eye函数
- start_time = time.time()
- onehot_matrix = torch.eye(4)
- onehot_sequences2 = []
- for sequence in sequences:
- index_sequence = [mapping[base] for base in sequence]
- onehot_sequence = onehot_matrix[index_sequence]
- onehot_sequences2.append(onehot_sequence)
- end_time = time.time()
- method2_time = end_time - start_time
- # 方法三:numpy进行转换
- start_time = time.time()
- onehot_matrix = np.eye(4)
- onehot_sequences3 = []
- for sequence in sequences:
- index_sequence = [mapping[base] for base in sequence]
- onehot_sequence = onehot_matrix[index_sequence]
- onehot_sequences3.append(onehot_sequence)
- onehot_sequences3 = torch.from_numpy(np.array(onehot_sequences3)).float()
- end_time = time.time()
- method3_time = end_time - start_time
- print("Method 1 time:", method1_time)
- print("Method 2 time:", method2_time)
- print("Method 3 time:", method3_time)
测试结果:
- Method 1 time: 0.09143757820129395
- Method 2 time: 0.02177143096923828
- Method 3 time: 0.035161733627319336