3.1 利用MNIST数据集做手写数字识别
from __future__ import print_function
import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
import torchvision
import torchvision.transforms as transforms
import matplotlib.pyplot as plt
import numpy as np
首先,设置超参数:
BATCH_SIZE=512 #大概需要2G的显存
EPOCHS=20 # 总共训练批次
# 让torch判断是否使用GPU,建议使用GPU环境,因为会快很多
DEVICE = torch.device("cuda" if torch.cuda.is_available() else "cpu")
从pytorch里面导入此次使用的mnist数据包:
transform = transforms.Compose(
[transforms.ToTensor(),
transforms.Normalize((0.1307,),(0.3081,))])
trainset = torchvision.datasets.MNIST(root='./data', train=True, transform=transform,
download=True)
train_loader = torch.utils.data.DataLoader(trainset,batch_size=BATCH_SIZE,shuffle=True)
testset = torchvision.datasets.MNIST(root='./data', train=False, transform=transform,
download=True)
test_loader = torch.utils.<