解释这段代码 import numpy as np import torch as pt import torchvision as ptv train_set = ptv.datasets.MNIST("src/step1/mnist/train", train=True, transform=ptv.transforms.ToTensor(), download=True) test_set = ptv.datasets.MNIST("src/step1/mnist/test", train=Fal
时间: 2024-03-19 10:40:54 浏览: 14
这段代码是一个 PyTorch 脚本,用于加载 MNIST 数据集并进行转换。MNIST 是一个常用的手写数字识别数据集,包含了大量的手写数字图片及其对应的标签。这个数据集通常被用作机器学习算法的基准测试数据集。
这段代码首先导入了需要用到的三个 Python 库:NumPy、PyTorch 和 Torchvision。NumPy 是一个常用的科学计算库,PyTorch 是一个基于 Python 的机器学习库,而 Torchvision 是 PyTorch 的一个视觉库,提供了许多用于图像处理的工具函数和数据集。
接着,代码定义了两个数据集对象:train_set 和 test_set。这两个对象都是 MNIST 数据集的实例。其中,train_set 是用于训练模型的数据集,而 test_set 是用于测试模型的数据集。
在定义数据集时,我们可以指定一些转换操作。在这个例子中,我们使用了 ptv.transforms.ToTensor(),它可以将 PIL 图像或 ndarray 转换成范围在 0~1 之间的 torch.Tensor,并将通道维度放在最前面。
最后,代码指定了 MNIST 数据集的存储路径,并且调用了 download=True 参数,以下载并存储数据集。
相关问题
基于以下代码,加入图像高斯模糊处理代码:import torch import torch.nn as nn import torch.optim as optim import torch.nn.functional as F from torchvision import datasets,transforms import matplotlib.pyplot as plt import numpy as np import pylab %matplotlib inline # 定义超参数 input_size = 28 #图像的总尺寸28*28 num_classes = 10 #标签的种类数 num_epochs = 10 #训练的总循环周期 batch_size = 64 #一个撮(批次)的大小,64张图片 # 训练集 train_dataset = datasets.MNIST(root='./data', train=True, transform=transforms.ToTensor(), download=True) # 测试集 test_dataset = datasets.MNIST(root='./data', train=False, transform=transforms.ToTensor()) # 构建batch数据 train_loader = torch.utils.data.DataLoader(dataset=train_dataset, batch_size=batch_size, shuffle=True) test_loader = torch.utils.data.DataLoader(dataset=test_dataset, batch_size=batch_size, shuffle=True)
可以将以下代码加入到定义超参数的代码块后面,实现对训练集和测试集图像的高斯模糊处理:
```
# 定义高斯模糊的卷积核
blur_kernel = np.array([[1, 2, 1],
[2, 4, 2],
[1, 2, 1]]) / 16.
# 定义高斯模糊的函数
def gaussian_blur(x):
x = np.array(x)
_, c, h, w = x.shape
blur_kernel_tensor = torch.from_numpy(blur_kernel).unsqueeze(0).repeat(c, 1, 1, 1).float().to(x.device)
x_blur = F.conv2d(x, blur_kernel_tensor, padding=(1, 1))
return x_blur
# 对训练集图像进行高斯模糊处理
for i, (images, labels) in enumerate(train_loader):
train_loader.dataset.data[i*batch_size:(i+1)*batch_size] = gaussian_blur(images).squeeze().detach().numpy()*255
# 对测试集图像进行高斯模糊处理
for i, (images, labels) in enumerate(test_loader):
test_loader.dataset.data[i*batch_size:(i+1)*batch_size] = gaussian_blur(images).squeeze().detach().numpy()*255
```
注意,由于 MNIST 数据集中的像素值范围为 0~255,高斯模糊处理后的像素值可能会出现小数,需要将其乘以 255 后转换为整数的像素值。
修改一下这段代码在pycharm中的实现,import pandas as pd import numpy as np from sklearn.model_selection import train_test_split import torch import torch.nn as nn import torch.nn.functional as F import torch.optim as optim #from torchvision import datasets,transforms import torch.utils.data as data #from torch .nn:utils import weight_norm import matplotlib.pyplot as plt from sklearn.metrics import precision_score from sklearn.metrics import recall_score from sklearn.metrics import f1_score from sklearn.metrics import cohen_kappa_score data_ = pd.read_csv(open(r"C:\Users\zhangjinyue\Desktop\rice.csv"),header=None) data_ = np.array(data_).astype('float64') train_data =data_[:,:520] train_Data =np.array(train_data).astype('float64') train_labels=data_[:,520] train_labels=np.array(train_data).astype('float64') train_data,train_data,train_labels,train_labels=train_test_split(train_data,train_labels,test_size=0.33333) train_data=torch.Tensor(train_data) train_data=torch.LongTensor(train_labels) train_data=train_data.reshape(-1,1,20,26) train_data=torch.Tensor(train_data) train_data=torch.LongTensor(train_labels) train_data=train_data.reshape(-1,1,20,26) start_epoch=1 num_epoch=1 BATCH_SIZE=70 Ir=0.001 classes=('0','1','2','3','4','5') device=torch.device("cuda"if torch.cuda.is_available()else"cpu") torch.backends.cudnn.benchmark=True best_acc=0.0 train_dataset=data.TensorDataset(train_data,train_labels) test_dataset=data.TensorDataset(train_data,train_labels) train_loader=torch.utills.data.DataLoader(dtaset=train_dataset,batch_size=BATCH_SIZE,shuffle=True) test_loader=torch.utills.data.DataLoader(dtaset=train_dataset,batch_size=BATCH_SIZE,shuffle=True)
修改后的代码如下所示:
```python
import pandas as pd
import numpy as np
from sklearn.model_selection import train_test_split
import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
import torch.utils.data as data
import matplotlib.pyplot as plt
from sklearn.metrics import precision_score, recall_score, f1_score, cohen_kappa_score
data_ = pd.read_csv(r"C:\Users\zhangjinyue\Desktop\rice.csv", header=None)
data_ = np.array(data_).astype('float64')
train_data = data_[:, :520]
train_labels = data_[:, 520]
train_data, _, train_labels, _ = train_test_split(train_data, train_labels, test_size=0.33333)
train_data = torch.Tensor(train_data)
train_labels = torch.LongTensor(train_labels)
train_data = train_data.reshape(-1, 1, 20, 26)
start_epoch = 1
num_epoch = 1
BATCH_SIZE = 70
Ir = 0.001
classes = ('0', '1', '2', '3', '4', '5')
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
torch.backends.cudnn.benchmark = True
best_acc = 0.0
train_dataset = data.TensorDataset(train_data, train_labels)
test_dataset = data.TensorDataset(train_data, train_labels)
train_loader = torch.utils.data.DataLoader(dataset=train_dataset, batch_size=BATCH_SIZE, shuffle=True)
test_loader = torch.utils.data.DataLoader(dataset=train_dataset, batch_size=BATCH_SIZE, shuffle=True)
```
请注意,我做了以下修改:
1. 移除了不需要的导入语句。
2. 修复了变量名拼写错误。
3. 移除了重复的代码行。
4. 修正了 `torch.utils.data.DataLoader` 的拼写错误。
5. 修正了数据集分割时的变量名错误。
请根据你的实际需求进一步调整代码。