(附代码)经验 | 深度学习pytorch训练代码模板
目标检测与深度学习
共 5877字,需浏览 12分钟
·
2021-09-20 21:51
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链接|https://zhuanlan.zhihu.com/p/396666255
01
import numpy as np
import torch
import torch.nn as nn
import numpy as np
import pandas as pd
from torch.utils.data import DataLoader, Dataset
from sklearn.model_selection import train_test_split
import matplotlib.pyplot as plt
import random
seed = 42
torch.manual_seed(seed)
np.random.seed(seed)
random.seed(seed)
02
class argparse():
pass
args = argparse()
args.epochs, args.learning_rate, args.patience = [30, 0.001, 4]
args.hidden_size, args.input_size= [40, 30]
args.device, = [torch.device("cuda:0" if torch.cuda.is_available() else "cpu"),]
03
定义自己的模型
class Your_model(nn.Module):
def __init__(self):
super(Your_model, self).__init__()
pass
def forward(self,x):
pass
return x
04
class EarlyStopping():
def __init__(self,patience=7,verbose=False,delta=0):
self.patience = patience
self.verbose = verbose
self.counter = 0
self.best_score = None
self.early_stop = False
self.val_loss_min = np.Inf
self.delta = delta
def __call__(self,val_loss,model,path):
print("val_loss={}".format(val_loss))
score = -val_loss
if self.best_score is None:
self.best_score = score
self.save_checkpoint(val_loss,model,path)
elif score < self.best_score+self.delta:
self.counter+=1
print(f'EarlyStopping counter: {self.counter} out of {self.patience}')
if self.counter>=self.patience:
self.early_stop = True
else:
self.best_score = score
self.save_checkpoint(val_loss,model,path)
self.counter = 0
def save_checkpoint(self,val_loss,model,path):
if self.verbose:
print(
f'Validation loss decreased ({self.val_loss_min:.6f} --> {val_loss:.6f}). Saving model ...')
torch.save(model.state_dict(), path+'/'+'model_checkpoint.pth')
self.val_loss_min = val_loss
05
class Dataset_name(Dataset):
def __init__(self, flag='train'):
assert flag in ['train', 'test', 'valid']
self.flag = flag
self.__load_data__()
def __getitem__(self, index):
pass
def __len__(self):
pass
def __load_data__(self, csv_paths: list):
pass
print(
"train_X.shape:{}\ntrain_Y.shape:{}\nvalid_X.shape:{}\nvalid_Y.shape:{}\n"
.format(self.train_X.shape, self.train_Y.shape, self.valid_X.shape, self.valid_Y.shape))
train_dataset = Dataset_name(flag='train')
train_dataloader = DataLoader(dataset=train_dataset, batch_size=64, shuffle=True)
valid_dataset = Dataset_name(flag='valid')
valid_dataloader = DataLoader(dataset=valid_dataset, batch_size=64, shuffle=True)
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model = Your_model().to(args.device)
criterion = torch.nn.MSELoss()
optimizer = torch.optim.Adam(Your_model.parameters(),lr=args.learning_rate)
train_loss = []
valid_loss = []
train_epochs_loss = []
valid_epochs_loss = []
early_stopping = EarlyStopping(patience=args.patience,verbose=True)
07
for epoch in range(args.epochs):
Your_model.train()
train_epoch_loss = []
for idx,(data_x,data_y) in enumerate(train_dataloader,0):
data_x = data_x.to(torch.float32).to(args.device)
data_y = data_y.to(torch.float32).to(args.device)
outputs = Your_model(data_x)
optimizer.zero_grad()
loss = criterion(data_y,outputs)
loss.backward()
optimizer.step()
train_epoch_loss.append(loss.item())
train_loss.append(loss.item())
if idx%(len(train_dataloader)//2)==0:
print("epoch={}/{},{}/{}of train, loss={}".format(
epoch, args.epochs, idx, len(train_dataloader),loss.item()))
train_epochs_loss.append(np.average(train_epoch_loss))
#=====================valid============================
Your_model.eval()
valid_epoch_loss = []
for idx,(data_x,data_y) in enumerate(valid_dataloader,0):
data_x = data_x.to(torch.float32).to(args.device)
data_y = data_y.to(torch.float32).to(args.device)
outputs = Your_model(data_x)
loss = criterion(outputs,data_y)
valid_epoch_loss.append(loss.item())
valid_loss.append(loss.item())
valid_epochs_loss.append(np.average(valid_epoch_loss))
#==================early stopping======================
early_stopping(valid_epochs_loss[-1],model=Your_model,path=r'c:\\your_model_to_save')
if early_stopping.early_stop:
print("Early stopping")
break
#====================adjust lr========================
lr_adjust = {
2: 5e-5, 4: 1e-5, 6: 5e-6, 8: 1e-6,
10: 5e-7, 15: 1e-7, 20: 5e-8
}
if epoch in lr_adjust.keys():
lr = lr_adjust[epoch]
for param_group in optimizer.param_groups:
param_group['lr'] = lr
print('Updating learning rate to {}'.format(lr))
08
plt.figure(figsize=(12,4))
plt.subplot(121)
plt.plot(train_loss[:])
plt.title("train_loss")
plt.subplot(122)
plt.plot(train_epochs_loss[1:],'-o',label="train_loss")
plt.plot(valid_epochs_loss[1:],'-o',label="valid_loss")
plt.title("epochs_loss")
plt.legend()
plt.show()
09
# 此处可定义一个预测集的Dataloader。也可以直接将你的预测数据reshape,添加batch_size=1
Your_model.eval()
predict = Your_model(data)
END
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