解释这段代码: if train: np.random.shuffle(data) self.X_train = data[:, :-10, :] self.y_train = data[:, -10:, 0] # telemetry value is at position 0 else: self.X_test = data[:, :-self.config.n_predictions, :] self.y_test = data[:, -self.config.n_predictions:, 0] # telemetry value is at position 0
时间: 2023-12-06 14:43:45 浏览: 35
这段代码是一个 Python 类中的初始化函数,根据传入的参数 `train` 和 `data` 初始化类的成员变量 `X_train`, `y_train`, `X_test` 和 `y_test`。
如果 `train` 参数为 `True`,则先使用 `np.random.shuffle()` 函数随机打乱输入数据 `data` 的顺序。接着,将 `data` 按照切片的方式分成两部分,即 `data[:, :-10, :]` 和 `data[:, -10:, 0]`。前者表示输入数据的前 `n-10` 个时间步骤的所有特征,后者表示输入数据的后 `10` 个时间步骤的第一个特征值,即模型要预测的值。最后,将这两部分数据分别赋值给成员变量 `X_train` 和 `y_train`。
如果 `train` 参数为 `False`,则将 `data` 按照切片的方式分成两部分,即 `data[:, :-self.config.n_predictions, :]` 和 `data[:, -self.config.n_predictions:, 0]`。前者表示输入数据的前 `n - self.config.n_predictions` 个时间步骤的所有特征,后者表示输入数据的后 `self.config.n_predictions` 个时间步骤的第一个特征值,即模型要预测的值。最后,将这两部分数据分别赋值给成员变量 `X_test` 和 `y_test`。
相关问题
def dataSetBalanceAllocation(self): mnistDataSet = GetDataSet(self.data_set_name, self.is_iid) test_data = torch.tensor(mnistDataSet.test_data) test_label = torch.argmax(torch.tensor(mnistDataSet.test_label), dim=1) self.test_data_loader = DataLoader(TensorDataset( test_data, test_label), batch_size=100, shuffle=False) train_data = mnistDataSet.train_data train_label = mnistDataSet.train_label shard_size = mnistDataSet.train_data_size // self.num_of_clients // 2 shards_id = np.random.permutation(mnistDataSet.train_data_size // shard_size) #permutation:排列 for i in range(self.num_of_clients): shards_id1 = shards_id[i * 2] shards_id2 = shards_id[i * 2 + 1] data_shards1 = train_data[shards_id1 * shard_size: shards_id1 * shard_size + shard_size] data_shards2 = train_data[shards_id2 * shard_size: shards_id2 * shard_size + shard_size] label_shards1 = train_label[shards_id1 * shard_size: shards_id1 * shard_size + shard_size] label_shards2 = train_label[shards_id2 * shard_size: shards_id2 * shard_size + shard_size] local_data, local_label = np.vstack((data_shards1, data_shards2)), np.vstack((label_shards1, label_shards2)) # vstack:data和label拼接 local_label = np.argmax(local_label, axis=1) someone = client(TensorDataset(torch.tensor(local_data), torch.tensor(local_label)), self.dev) self.clients_set['client{}'.format(i)] = someone 解释这段代码
这段代码是一个类中的方法`dataSetBalanceAllocation()`。该方法用于对数据集进行平衡分配给多个客户端。
首先,通过调用`GetDataSet()`函数获取`mnistDataSet`数据集对象。然后,将测试数据和测试标签转换为张量,并使用`DataLoader`创建一个测试数据加载器,每个批次大小为100,不打乱顺序。
接下来,将训练数据和训练标签存储在`train_data`和`train_label`中。然后,计算每个客户端的数据分片大小,即`shard_size`,它是训练数据总量除以客户端数量除以2(因为每个客户端获取两个分片)。
通过使用`np.random.permutation()`函数对`mnistDataSet.train_data_size // shard_size`进行排列,得到一个随机的分片索引数组`shards_id`。
接下来,使用循环为每个客户端分配数据。在每次迭代中,通过索引数组`shards_id`获取两个分片的索引`shards_id1`和`shards_id2`。然后,通过这些索引从训练数据和标签中选择对应的数据分片。将这些分片堆叠起来,形成本地的数据和标签,并将其封装为`TensorDataset`对象。
然后,创建一个名为`someone`的客户端对象,该对象是使用上述本地数据和标签创建的。将该客户端对象添加到`self.clients_set`字典中,键为`'client{}'.format(i)`。
通过这样的操作,数据集被平衡地分配给了多个客户端,每个客户端都有两个数据分片。你可以通过访问`self.clients_set`来访问每个客户端的数据和标签。
LDAM损失函数pytorch代码如下:class LDAMLoss(nn.Module): def init(self, cls_num_list, max_m=0.5, weight=None, s=30): super(LDAMLoss, self).init() m_list = 1.0 / np.sqrt(np.sqrt(cls_num_list)) m_list = m_list * (max_m / np.max(m_list)) m_list = torch.cuda.FloatTensor(m_list) self.m_list = m_list assert s > 0 self.s = s if weight is not None: weight = torch.FloatTensor(weight).cuda() self.weight = weight self.cls_num_list = cls_num_list def forward(self, x, target): index = torch.zeros_like(x, dtype=torch.uint8) index_float = index.type(torch.cuda.FloatTensor) batch_m = torch.matmul(self.m_list[None, :], index_float.transpose(1,0)) # 0,1 batch_m = batch_m.view((16, 1)) # size=(batch_size, 1) (-1,1) x_m = x - batch_m output = torch.where(index, x_m, x) if self.weight is not None: output = output * self.weight[None, :] target = torch.flatten(target) # 将 target 转换成 1D Tensor logit = output * self.s return F.cross_entropy(logit, target, weight=self.weight) 模型部分参数如下:# 设置全局参数 model_lr = 1e-5 BATCH_SIZE = 16 EPOCHS = 50 DEVICE = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu') use_amp = True use_dp = True classes = 7 resume = None CLIP_GRAD = 5.0 Best_ACC = 0 #记录最高得分 use_ema=True model_ema_decay=0.9998 start_epoch=1 seed=1 seed_everything(seed) # 数据增强 mixup mixup_fn = Mixup( mixup_alpha=0.8, cutmix_alpha=1.0, cutmix_minmax=None, prob=0.1, switch_prob=0.5, mode='batch', label_smoothing=0.1, num_classes=classes) # 读取数据集 dataset_train = datasets.ImageFolder('/home/adminis/hpy/ConvNextV2_Demo/RAF-DB/RAF/train', transform=transform) dataset_test = datasets.ImageFolder("/home/adminis/hpy/ConvNextV2_Demo/RAF-DB/RAF/valid", transform=transform_test)# 导入数据 train_loader = torch.utils.data.DataLoader(dataset_train, batch_size=BATCH_SIZE, shuffle=True,drop_last=True) test_loader = torch.utils.data.DataLoader(dataset_test, batch_size=BATCH_SIZE, shuffle=False) 帮我用pytorch实现模型在模型训练中使用LDAM损失函数
好的,以下是使用LDAM损失函数训练模型的Pytorch代码:
```python
import torch
import torch.nn as nn
import torch.nn.functional as F
import numpy as np
from torchvision import datasets, transforms
from ldam_loss import LDAMLoss
# 定义模型
class MyModel(nn.Module):
def __init__(self, num_classes):
super(MyModel, self).__init__()
self.num_classes = num_classes
self.features = nn.Sequential(
nn.Conv2d(3, 32, kernel_size=3, stride=1, padding=1),
nn.BatchNorm2d(32),
nn.ReLU(inplace=True),
nn.MaxPool2d(kernel_size=2, stride=2),
nn.Conv2d(32, 64, kernel_size=3, stride=1, padding=1),
nn.BatchNorm2d(64),
nn.ReLU(inplace=True),
nn.MaxPool2d(kernel_size=2, stride=2),
nn.Conv2d(64, 128, kernel_size=3, stride=1, padding=1),
nn.BatchNorm2d(128),
nn.ReLU(inplace=True),
nn.MaxPool2d(kernel_size=2, stride=2),
)
self.classifier = nn.Sequential(
nn.Linear(128 * 4 * 4, 256),
nn.ReLU(inplace=True),
nn.Linear(256, num_classes),
)
def forward(self, x):
x = self.features(x)
x = x.view(x.size(0), -1)
x = self.classifier(x)
return x
# 设置超参数
model_lr = 1e-4
BATCH_SIZE = 16
EPOCHS = 50
DEVICE = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu')
use_amp = True
use_dp = True
classes = 7
resume = None
CLIP_GRAD = 5.0
Best_ACC = 0
use_ema = True
model_ema_decay = 0.9998
start_epoch = 1
seed = 1
# 设置随机种子
def seed_everything(seed):
torch.manual_seed(seed)
torch.cuda.manual_seed_all(seed)
np.random.seed(seed)
seed_everything(seed)
# 定义数据增强
transform = transforms.Compose([
transforms.Resize(224),
transforms.RandomHorizontalFlip(),
transforms.RandomRotation(10),
transforms.ToTensor(),
transforms.Normalize(mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225])
])
transform_test = transforms.Compose([
transforms.Resize(224),
transforms.ToTensor(),
transforms.Normalize(mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225])
])
# 定义数据集
dataset_train = datasets.ImageFolder('/home/adminis/hpy/ConvNextV2_Demo/RAF-DB/RAF/train', transform=transform)
dataset_test = datasets.ImageFolder("/home/adminis/hpy/ConvNextV2_Demo/RAF-DB/RAF/valid", transform=transform_test)
# 定义数据加载器
train_loader = torch.utils.data.DataLoader(dataset_train, batch_size=BATCH_SIZE, shuffle=True, drop_last=True)
test_loader = torch.utils.data.DataLoader(dataset_test, batch_size=BATCH_SIZE, shuffle=False)
# 定义模型及优化器
model = MyModel(num_classes=classes).to(DEVICE)
optimizer = torch.optim.Adam(model.parameters(), lr=model_lr)
# 使用LDAM损失函数
cls_num_list = [dataset_train.targets.count(i) for i in range(classes)]
criterion = LDAMLoss(cls_num_list=cls_num_list, max_m=0.5, weight=None, s=30)
# 训练模型
for epoch in range(start_epoch, EPOCHS+1):
model.train()
for i, (data, target) in enumerate(train_loader):
data, target = data.to(DEVICE), target.to(DEVICE)
mixup_data, mixup_target = mixup_fn(data, target) # 数据增强
optimizer.zero_grad()
output = model(mixup_data)
loss = criterion(output, mixup_target)
if use_dp:
loss.backward()
torch.nn.utils.clip_grad_norm_(model.parameters(), CLIP_GRAD)
else:
with amp.scale_loss(loss, optimizer) as scaled_loss:
scaled_loss.backward()
torch.nn.utils.clip_grad_norm_(amp.master_params(optimizer), CLIP_GRAD)
optimizer.step()
if use_ema:
ema_model = ModelEMA(model, decay=model_ema_decay)
ema_model.update(model)
else:
ema_model = None
test_acc = test(model, test_loader, DEVICE)
if test_acc > Best_ACC:
Best_ACC = test_acc
save_checkpoint({
'epoch': epoch,
'state_dict': model.state_dict(),
'optimizer': optimizer.state_dict(),
'Best_ACC': Best_ACC,
}, is_best=True)
```