out = torch.mean(out.permute(1, 0, 2), 1) 是什么意思
时间: 2023-10-30 20:06:33 浏览: 45
这是一个 PyTorch 的操作,它的作用是对输入的 tensor 进行操作,具体地说,它将输入的 tensor 进行转置,然后再对转置后的 tensor 进行平均池化操作。其中,`out` 是一个形状为 `(seq_len, batch_size, hidden_size)` 的 tensor。
具体来说,`out.permute(1, 0, 2)` 的作用是将 `out` 的维度进行转置,将原来的第 1 维转置到第 2 维,将原来的第 2 维转置到第 1 维,不变的是第 3 维。这样转置后,`out` 的维度变为 `(batch_size, seq_len, hidden_size)`。
然后,`torch.mean()` 函数对第 1 维(即 `seq_len`)进行平均池化,得到一个形状为 `(batch_size, hidden_size)` 的 tensor。最终的结果是将 `out` 沿着第 1 维进行平均池化,将每个样本的所有时刻的 hidden state 取平均,得到一个代表整个序列的向量。
相关问题
转化为paddlepaddle2.2.2代码:def safe_invert_gains(image, rgb_gain, red_gain, blue_gain): """Inverts gains while safely handling saturated pixels.""" image = image.permute(1, 2, 0) # Permute the image tensor to HxWxC format from CxHxW format gains = torch.stack((1.0 / red_gain, torch.tensor([1.0]), 1.0 / blue_gain)) / rgb_gain gains = gains.squeeze() gains = gains[None, None, :] # Prevents dimming of saturated pixels by smoothly masking gains near white. gray = torch.mean(image, dim=-1, keepdim=True) inflection = 0.9 mask = (torch.clamp(gray - inflection, min=0.0) / (1.0 - inflection)) ** 2.0 safe_gains = torch.max(mask + (1.0 - mask) * gains, gains) out = image * safe_gains out = out.permute(2, 0, 1) # Re-Permute the tensor back to CxHxW format return out
以下是将上述代码转换为PaddlePaddle 2.2.2的代码:
```
import paddle
import paddle.nn.functional as F
def safe_invert_gains(image, rgb_gain, red_gain, blue_gain):
"""Inverts gains while safely handling saturated pixels."""
image = paddle.transpose(image, perm=[1, 2, 0]) # Permute the image tensor to HxWxC format from CxHxW format
gains = paddle.stack((1.0 / red_gain, paddle.to_tensor([1.0]), 1.0 / blue_gain)) / rgb_gain
gains = paddle.squeeze(gains)
gains = gains.unsqueeze(0).unsqueeze(0) # Prevents dimming of saturated pixels by smoothly masking gains near white.
gray = paddle.mean(image, axis=-1, keepdim=True)
inflection = 0.9
mask = (F.relu(gray - inflection, inplace=True) / (1.0 - inflection)) ** 2.0
safe_gains = paddle.maximum(mask + (1.0 - mask) * gains, gains)
out = image * safe_gains
out = paddle.transpose(out, perm=[2, 0, 1]) # Re-Permute the tensor back to CxHxW format
return out
```
需要注意的是,PaddlePaddle中的API与PyTorch不完全一致,因此需要对代码做一些调整。主要包括:
1. 将torch转换为paddle。
2. 将permute函数转换为transpose函数,并调整参数格式。
3. 将torch.mean函数转换为paddle.mean,并调整参数格式。
4. 将torch.clamp函数转换为F.relu函数,并调整参数格式。
5. 将torch.max函数转换为paddle.maximum函数。
需要注意的是,在PaddlePaddle中,使用inplace=True时需要用F.relu等函数来代替。
我有一个CSV文件有机质是一列187行,特征值为38列187行希望使用上述代码
好的,如果您有一个 CSV 文件,其中有机质是一列 187 行,特征值为 38 列 187 行,可以按照以下步骤进行处理:
1.导入所需的库:
```
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.optim as optim
from torch.utils.data import TensorDataset, DataLoader
```
2.加载 CSV 文件并进行数据预处理:
```
# 加载 CSV 文件
data = pd.read_csv("data.csv")
# 将有机质和特征值分别存储在不同的变量中
labels = data.iloc[:, 0].values.astype(np.float32)
features = data.iloc[:, 1:].values.astype(np.float32)
# 对标签进行归一化处理
labels = (labels - labels.mean()) / labels.std()
# 将数据分为训练集和测试集
train_features, test_features, train_labels, test_labels = train_test_split(features, labels, test_size=0.2, random_state=42)
# 将数据转换为张量
train_features = torch.from_numpy(train_features)
test_features = torch.from_numpy(test_features)
train_labels = torch.from_numpy(train_labels)
test_labels = torch.from_numpy(test_labels)
# 将数据转换为数据集和数据加载器
train_dataset = TensorDataset(train_features, train_labels)
test_dataset = TensorDataset(test_features, test_labels)
train_loader = DataLoader(train_dataset, batch_size=100, shuffle=True)
test_loader = DataLoader(test_dataset, batch_size=100, shuffle=False)
```
在这个例子中,我们使用 pandas 库加载 CSV 文件,并将有机质和特征值分别存储在 labels 和 features 变量中。然后,我们对标签进行归一化处理,并将数据分为训练集和测试集。最后,我们将数据转换为张量,并使用 PyTorch 的 TensorDataset 和 DataLoader 将数据转换为数据集和数据加载器。
3.定义模型:
```
class ConvNet(nn.Module):
def __init__(self):
super(ConvNet, self).__init__()
self.layer1 = nn.Sequential(
nn.Conv1d(38, 32, kernel_size=3, stride=1, padding=1),
nn.BatchNorm1d(32),
nn.ReLU(),
nn.MaxPool1d(kernel_size=2, stride=2))
self.layer2 = nn.Sequential(
nn.Conv1d(32, 64, kernel_size=3, stride=1, padding=1),
nn.BatchNorm1d(64),
nn.ReLU(),
nn.MaxPool1d(kernel_size=2, stride=2))
self.layer3 = nn.Sequential(
nn.Conv1d(64, 128, kernel_size=3, stride=1, padding=1),
nn.BatchNorm1d(128),
nn.ReLU(),
nn.MaxPool1d(kernel_size=2, stride=2))
self.fc = nn.Linear(128, 1)
def forward(self, x):
out = self.layer1(x)
out = self.layer2(out)
out = self.layer3(out)
out = out.reshape(out.size(0), -1)
out = self.fc(out)
return out
```
在这个例子中,我们定义了一个与之前例子相同的卷积神经网络模型,区别在于输入特征数从 1 改为了 38,输出类别数为 1。
4.定义训练函数和测试函数:
```
def train(model, train_loader, criterion, optimizer, num_epochs):
total_step = len(train_loader)
for epoch in range(num_epochs):
for i, (features, labels) in enumerate(train_loader):
outputs = model(features.permute(0, 2, 1))
loss = criterion(outputs, labels.unsqueeze(1))
optimizer.zero_grad()
loss.backward()
optimizer.step()
if (i+1) % 100 == 0:
print ('Epoch [{}/{}], Step [{}/{}], Loss: {:.4f}'.format(epoch+1, num_epochs, i+1, total_step, loss.item()))
def test(model, test_loader):
with torch.no_grad():
correct = 0
total = 0
for features, labels in test_loader:
outputs = model(features.permute(0, 2, 1))
predicted = torch.round(outputs)
total += labels.size(0)
correct += (predicted == labels.unsqueeze(1)).sum().item()
print('Accuracy of the network on the test set: {} %'.format(100 * correct / total))
```
在训练函数中,我们使用交叉熵损失函数和随机梯度下降优化器进行训练;在测试函数中,我们计算模型在测试集上的准确率。
5.初始化模型、定义损失函数和优化器,并进行训练和测试:
```
# 初始化模型
model = ConvNet()
# 定义损失函数和优化器
criterion = nn.MSELoss()
optimizer = optim.Adam(model.parameters(), lr=0.01)
# 训练模型
train(model, train_loader, criterion, optimizer, num_epochs=5)
# 测试模型
test(model, test_loader)
```
在这个例子中,我们使用均方误差损失函数和 Adam 优化器进行训练,学习率为 0.01,训练 5 个 epoch。最后,我们在测试集上计算了模型的准确率。
以上就是基于 PyTorch 搭建多特征一维卷积神经网络的完整代码,希望对您有所帮助。