我正在尝试实现 NiN 模型。基本上试图从d2l复制代码这是我的代码。
import pandas as pd
import torch
from torch import nn
import torchmetrics
from torchvision import transforms
from torch.utils.data import DataLoader, random_split
import pytorch_lightning as pl
from torchvision.datasets import FashionMNIST
import wandb
from pytorch_lightning.loggers import WandbLogger
wandb.login()
## class definition
class Lightning_nin(pl.LightningModule):
def __init__(self):
super().__init__()
self.accuracy = torchmetrics.Accuracy(top_k=1)
self.model = nn.Sequential(
self.nin_block(1, 96, kernel_size=11, strides=4, padding=0),
nn.MaxPool2d(3, stride=2),
self.nin_block(96, 256, kernel_size=5, strides=1, padding=2),
nn.MaxPool2d(3, stride=2),
self.nin_block(256, 384, kernel_size=3, strides=1, padding=1),
nn.MaxPool2d(3, stride=2), nn.Dropout(0.5),
# There are 10 label classes
self.nin_block(384, 10, kernel_size=3, strides=1, padding=1),
nn.AdaptiveAvgPool2d((1, 1)),
# Transform the four-dimensional output into two-dimensional output with a
# shape of (batch size, 10)
nn.Flatten())
for layer in self.model:
if type(layer) == nn.Linear or type(layer) == nn.Conv2d:
nn.init.xavier_uniform_(layer.weight)
def nin_block(self,in_channels, out_channels, kernel_size, strides, padding):
return nn.Sequential(
nn.Conv2d(in_channels, out_channels, kernel_size, strides, padding),
nn.ReLU(), nn.Conv2d(out_channels, out_channels, kernel_size=1),
nn.ReLU(), nn.Conv2d(out_channels, out_channels, kernel_size=1),
nn.ReLU())
def forward(self, x):
x = self.model(x)
return x
def loss_fn(self,logits,y):
loss = nn.CrossEntropyLoss()
return loss(logits,y)
def training_step(self,train_batch,batch_idx):
X, y = train_batch
logits = self.forward(X)
loss = self.loss_fn(logits,y)
self.log('train_loss',loss)
m = nn.Softmax(dim=1)
output = m(logits)
self.log('train_acc',self.accuracy(output,y))
return loss
def validation_step(self,val_batch,batch_idx):
X,y = val_batch
logits = self.forward(X)
loss = self.loss_fn(logits,y)
self.log('test_loss',loss)
m = nn.Softmax(dim=1)
output = m(logits)
self.log('test_acc',self.accuracy(output,y))
def configure_optimizers(self):
optimizer = torch.optim.SGD(self.model.parameters(),lr= 0.1)
return optimizer
class Light_DataModule(pl.LightningDataModule):
def __init__(self,resize= None):
super().__init__()
if resize:
self.resize = resize
def setup(self, stage):
# transforms for images
trans = [transforms.ToTensor()]
if self.resize:
trans.insert(0, transforms.Resize(self.resize))
trans = transforms.Compose(trans)
# prepare transforms standard to MNIST
self.mnist_train = FashionMNIST(root="../data", train=True, download=True, transform=trans)
self.mnist_test = FashionMNIST(root="../data", train=False, download=True, transform=trans)
def train_dataloader(self):
return DataLoader(self.mnist_train, batch_size=128,shuffle=True,num_workers=4)
def val_dataloader(self):
return DataLoader(self.mnist_test, batch_size=128,num_workers=4)
## Train model
data_module = Light_DataModule(resize=224)
wandb_logger = WandbLogger(project="d2l",name ='NIN')
model = Lightning_nin()
trainer = pl.Trainer(logger=wandb_logger,max_epochs=4,gpus=1,progress_bar_refresh_rate =1)
trainer.fit(model, data_module)
wandb.finish()
运行代码后，我的准确度仅为 0.1。不知道我哪里出错了。我已经能够使用相同的模板实现其他 CNN（如 VGG）。不知道我哪里出错了。10 个 epoch 后准确率应该接近 0.9。