train_dataset = datasets.MNIST(root='./data/', train=True, transform=transforms.ToTensor(), download=False)什么意思

train_data-数据集

train set-数据集

train_X.txt

train数据集

train数据集，公开数据集 train数据集，公开数据集 train数据集，公开数据集 train数据集，公开数据集

解释这段代码train_dataset = datasets.MNIST(root='mnist', train=True, transform=transforms.ToTensor(), download=True)

这段代码定义了一个名为train_dataset的变量，它使用datasets.MNIST函数从MNIST数据集中加载训练数据，并使用transforms.ToTensor函数将其转换为张量，最后将download参数

import torch import torchvision import torch.nn as nn import torchvision.transforms as transforms #超参数 num_classes = 10 #类别个数 num_epochs = 10 #迭代次数/训练次数 learning_rate = 0.01 #学习率，方法更新的速率 batch_size = 64 #批次，批量大小，每次传输图片的个数 #训练集 train_dataset = torchvision.datasets.MNIST(root = './data', train = True, download = True, transform = transforms.Compose([ transforms.Resize((28,28)),transforms.ToTensor()]) ) #测试集 test_dataset = torchvision.datasets.MNIST(root = './data', train = False, download = True, transform = transforms.Compose([ transforms.Resize((28,28)),transforms.ToTensor()]) )

使用了transforms.Compose()函数来将多个预处理操作组合起来。这里使用了两个预处理操作：Resize将图像大小调整为28x28像素，ToTensor将图像转换为Tensor类型。这样，训练集和测试集的数据集对象就创建好了。接...

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)

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): ...

train_dataset = datasets.MNIST(dir, train=True, download=True, transform=transforms.ToTensor())什么意思

- transform=transforms.ToTensor() 表示将数据集中的图像数据转换为 PyTorch 中的 tensor 格式。这行代码的作用是将 MNIST 数据集加载到内存中，并将其转换为 PyTorch 中的 tensor 格式，以便后续进行机器学习...

transform=transforms.Compose([ transforms.ToTensor(), transforms.Normalize((0.1307,), (0.3081,)) ]) dataset1 = datasets.MNIST('../data_row', train=True, download=True, transform=transform) dataset2 = datasets.MNIST('../data_row', train=False, transform=transform)

transforms.ToTensor() 将图像转换为张量(tensor)格式，transforms.Normalize() 则用于对图像进行归一化处理。接下来，代码通过 datasets.MNIST() 函数创建两个 MNIST 数据集对象。第一个对象 dataset1 是用于训练...

train_dataset = datasets.MNIST(root='D:\\dataset\\MNIST', train=True, download=True, transform=transform) train_loader = DataLoader(train_dataset, shuffle=True, batch_size=batch_size) test_dataset = datasets.MNIST(root='D:\\dataset\\MNIST', train=False, download=True, transform=transform) test_loader = DataLoader(test_dataset, shuffle=False, batch_size=batch_size) 怎么改变为.mat形式的输入

train_dataset = datasets.MNIST(root='D:\\dataset\\MNIST', train=True, download=True, transform=transform) test_dataset = datasets.MNIST(root='D:\\dataset\\MNIST', train=False, download=True, transform...

from model import Model import numpy as np import torch from torchvision.datasets import mnist from torch.nn import CrossEntropyLoss from torch.optim import SGD from torch.utils.data import DataLoader from torchvision.transforms import ToTensor if name == 'main': batch_size = 256 train_dataset = mnist.MNIST(root='./train', train=True, transform=ToTensor()) test_dataset = mnist.MNIST(root='./test', train=False, transform=ToTensor()) train_loader = DataLoader(train_dataset, batch_size=batch_size) test_loader = DataLoader(test_dataset, batch_size=batch_size) model = Model() sgd = SGD(model.parameters(), lr=1e-1) cost = CrossEntropyLoss() epoch = 100 for _epoch in range(epoch): model.train() for idx, (train_x, train_label) in enumerate(train_loader): label_np = np.zeros((train_label.shape[0], 10)) sgd.zero_grad() predict_y = model(train_x.float()) loss = cost(predict_y, train_label.long()) if idx % 10 == 0: print('idx: {}, loss: {}'.format(idx, loss.sum().item())) loss.backward() sgd.step() correct = 0 _sum = 0 model.eval() for idx, (test_x, test_label) in enumerate(test_loader): predict_y = model(test_x.float()).detach() predict_ys = np.argmax(predict_y, axis=-1) label_np = test_label.numpy() _ = predict_ys == test_label correct += np.sum(_.numpy(), axis=-1) _sum += _.shape[0] print('accuracy: {:.2f}'.format(correct / _sum)) torch.save(model, 'models/mnist_{:.2f}.pkl'.format(correct / _sum))

首先，它导入了所需的库和模块，包括了模型定义(Model)、数据集(mnist)、数据加载器(DataLoader)、损失函数(CrossEntropyLoss)、优化器(SGD)以及数据转换(ToTensor)。然后，在if __name__ == '__main...

如何导入语句train_dataset = datasets.ImageFolder(train_dir, transform=transform)中的datasets

在Python中，可以使用import语句导入模块或包。datasets是PyTorch中的一个模块，包含了...其中，train_dir是训练数据集的路径，transform是数据变换的方式，比如可以使用transforms.Compose()函数将多种变换组合起来。

import torch import torch.nn as nn import torch.optim as optim import torchvision.datasets as datasets import torchvision.transforms as transforms # 定义超参数 batch_size = 64 learning_rate = 0.001 num_epochs = 10 # 定义数据预处理 transform = transforms.Compose([ transforms.ToTensor(), # 转换为Tensor类型 transforms.Normalize((0.1307,), (0.3081,)) # 标准化，使得均值为0，标准差为1 ]) # 加载MNIST数据集 train_dataset = datasets.MNIST(root='C:/MNIST', train=True, transform=transform, download=True) test_dataset = datasets.MNIST(root='C:/MNIST', train=False, transform=transform, download=True) 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=False) # 定义CNN模型 class CNN(nn.Module): def init(self): super(CNN, self).init() self.conv1 = nn.Conv2d(1, 32, kernel_size=3, stride=1, padding=1) self.bn1 = nn.BatchNorm2d(32) self.relu1 = nn.ReLU() self.conv2 = nn.Conv2d(32, 64, kernel_size=3, stride=1, padding=1) self.bn2 = nn.BatchNorm2d(64) self.relu2 = nn.ReLU() self.pool = nn.MaxPool2d(kernel_size=2, stride=2) self.fc1 = nn.Linear(64 * 7 * 7, 128) self.relu3 = nn.ReLU() self.fc2 = nn.Linear(128, 10) def forward(self, x): out = self.conv1(x) out = self.bn1(out) out = self.relu1(out) out = self.conv2(out) out = self.bn2(out) out = self.relu2(out) out = self.pool(out) out = out.view(-1, 64 * 7 * 7) out = self.fc1(out) out = self.relu3(out) out = self.fc2(out) return out # 实例化模型并定义损失函数和优化器 model = CNN() criterion = nn.CrossEntropyLoss() optimizer = optim.Adam(model.parameters(), lr=learning_rate) # 训练模型 total_step = len(train_loader) for epoch in range(num_epochs): for i, (images, labels) in enumerate(train_loader): # 前向传播 outputs = model(images) loss = criterion(outputs, labels) # 反向传播和优化 optimizer.zero_grad() loss.backward() optimizer.step() # 每100个batch打印一次训练信息 if (i+1) % 100 == 0: print('Epoch [{}/{}], Step [{}/{}], Loss: {:.4f}' .format(epoch+1, num_epochs, i+1, total_step, loss.item())) # 测试模型 model.eval() # 进入测试模式，关闭Dropout和BatchNormalization层 with torch.no_grad(): correct = 0 total = 0 for images, labels in test_loader: outputs = model(images) _, predicted = torch.max(outputs.data, 1) total += labels.size(0) correct += (predicted == labels).sum().item() print('Test Accuracy of the model on the 10000 test images: {} %'.format(100 * correct / total))运行一下此代码

好的，运行这段代码需要先安装PyTorch...在运行之前，需要将代码中的数据集路径修改为本地路径，可以在代码中找到“root='C:/MNIST'”这一行将其修改为你的本地路径。运行后，模型会进行训练和测试，并输出测试准确率。

#加载内置数据集 train_ds = torchvision.datasets.MNIST('data',train=True,transform=transforms)

train_ds = torchvision.datasets.MNIST('data', train=True, transform=transforms) 这做了以下几个事情： 1. **路径指定**：'data' 参数指定了存储MNIST数据集文件的位置，默认在系统当前目录下查找。如果...

import numpy as np import paddle as paddle import paddle.fluid as fluid from PIL import Image import matplotlib.pyplot as plt import os from paddle.fluid.dygraph import Linear from paddle.vision.transforms import Compose, Normalize transform = Compose([Normalize(mean=[127.5],std=[127.5],data_format='CHW')]) print('下载并加载训练数据') train_dataset = paddle.vision.datasets.MNIST(mode='train', transform=transform) test_dataset = paddle.vision.datasets.MNIST(mode='test', transform=transform) print('加载完成') train_data0, train_label_0 = train_dataset[0][0],train_dataset[0][1] train_data0 = train_data0.reshape([28,28]) plt.figure(figsize=(2,2)) print(plt.imshow(train_data0, cmap=plt.cm.binary)) print('train_data0 的标签为: ' + str(train_label_0)) print(train_data0) class mnist(paddle.nn.Layer): def init(self): super(mnist,self).init() self.fc1 = paddle.fluid.dygraph.Linear(input_dim=28*28, output_dim=100, act='relu') self.fc2 = paddle.fluid.dygraph.Linear(input_dim=100, output_dim=100, act='relu') self.fc3 = paddle.fluid.dygraph.Linear(input_dim=100, output_dim=10,act="softmax") def forward(self, input_): x = fluid.layers.reshape(input_, [input_.shape[0], -1]) x = self.fc1(x) x = self.fc2(x) y = self.fc3(x) return y from paddle.metric import Accuracy model = paddle.Model(mnist()) optim = paddle.optimizer.Adam(learning_rate=0.001, parameters=model.parameters()) model.prepare(optim,paddle.nn.CrossEntropyLoss(),Accuracy()) model.fit(train_dataset,test_dataset,epochs=2,batch_size=64,save_dir='multilayer_perceptron',verbose=1) test_data0, test_label_0 = test_dataset[0][0],test_dataset[0][1] test_data0 = test_data0.reshape([28,28]) plt.figure(figsize=(2,2)) print(plt.imshow(test_data0, cmap=plt.cm.binary)) print('test_data0 的标签为: ' + str(test_label_0)) result = model.predict(test_dataset, batch_size=1) print('test_data0 预测的数值为：%d' % np.argsort(result[0][0])[0][-1]) 请给出这一段代码每一行的解释

14. 将train_dataset中第一张图片的图像数据和标签分别赋值给train_data0和train_label_0。 15. 将train_data0的形状转换为[28,28]。 16. 设置图像大小为(2,2)。 17. 使用plt.imshow绘制train_data0的灰度图像，颜色...

#encoding=utf8 import torch import torch.nn as nn from torch.autograd import Variable import torch.utils.data as Data import torchvision import os if os.path.exists('/data/workspace/course/step3/cnn.pkl'): os.remove('/data/workspace/course/step3/cnn.pkl') #加载数据 train_data = torchvision.datasets.MNIST( root='/data/workspace/course/step3/mnist', train=True, # this is training data transform=torchvision.transforms.ToTensor(), # Converts a PIL.Image or numpy.ndarray to download=False, ) #取6000个样本为训练集 train_data_tiny = [] for i in range(6000): train_data_tiny.append(train_data[i]) train_data = train_data_tiny #***** Begin # # End *****# #保存模型 torch.save(cnn.state_dict(), '/data/workspace/course/step3/cnn.pkl') 帮我补全begin-end区域代码

train_loader = Data.DataLoader(dataset=train_data, batch_size=64, shuffle=True) # 训练模型 for epoch in range(1): for step, (x, y) in enumerate(train_loader): b_x = Variable(x) # batch x b_y = ...

import torch import torch.nn as nn import torch.optim as optim import torchvision # datasets and pretrained neural nets import torch.utils.data import torch.nn.functional as F import torchvision.transforms as transforms transform = transforms.Compose([transforms.ToTensor(), ]) trainset = torchvision.datasets.MNIST(root='.\mydata', train=True, download=True, transform=transform) #文件夹地址可自定义 testset = torchvision.datasets.MNIST(root='.\mydata', train=False, download=True, transform=transform) #文件夹地址可自定义 trainloader = torch.utils.data.DataLoader(trainset, batch_size =32, shuffle=True) testloader = torch.utils.data.DataLoader(testset, batch_size=32, shuffle=False)写一个构建网络定义损失函数，优化器训练迭代次数为10次模型评测尝试将数据集更改为FashionMNIST或者CIFIR10再训练模型，或对比卷积神经网络和全连接神经网络模型的预测准确度，或尝试数据增强方法的代码

trainset = torchvision.datasets.FashionMNIST(root=data_root, train=True, download=True, transform=transforms.ToTensor()) testset = torchvision.datasets.FashionMNIST(root=data_root, train=False, ...

(x, y), (x_val, y_val) = datasets.mnist.load_data() x = tf.convert_to_tensor(x, dtype=tf.float32) / 255.

This code loads the popular MNIST dataset, which contains a large number of hand-written digit images. The first line assigns two tuples of data to the variables (x, y) and (x_val, y_val). x and...

train_dataset = datasets.MNIST(root='./data/', train=True, transform=transforms.ToTensor(), download=False)什么意思

相关推荐

train_data-数据集

train set-数据集

train数据集

解释这段代码train_dataset = datasets.MNIST(root='mnist', train=True, transform=transforms.ToTensor(), download=True)

train_dataset = datasets.MNIST(dir, train=True, download=True, transform=transforms.ToTensor())什么意思

transform=transforms.Compose([ transforms.ToTensor(), transforms.Normalize((0.1307,), (0.3081,)) ]) dataset1 = datasets.MNIST('../data_row', train=True, download=True, transform=transform) dataset2 = datasets.MNIST('../data_row', train=False, transform=transform)

如何导入语句train_dataset = datasets.ImageFolder(train_dir, transform=transform)中的datasets

#加载内置数据集 train_ds = torchvision.datasets.MNIST('data',train=True,transform=transforms)

(x, y), (x_val, y_val) = datasets.mnist.load_data() x = tf.convert_to_tensor(x, dtype=tf.float32) / 255.

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