池化层【马赛克】

最大池化，也叫下采样。

公式：

参数：

celling的意思：

例子：

尺寸：

code:

import torchimport torchvision.datasetsfrom tensorboardX import SummaryWriterfrom torch import nnfrom torch.nn import MaxPool2dfrom torch.utils.data import DataLoaderdataset = torchvision.datasets.CIFAR10("data",train=False,download=True,transform=torchvision.transforms.ToTensor())dataloader = DataLoader(dataset,batch_size=64)input = torch.tensor([[1,2,0,3,1],                      [0,1,2,3,1],                      [1,2,1,0,0],                      [5,2,3,1,1],                      [2,1,0,1,1]],dtype=torch.float32)input = torch.reshape(input,(-1,1,5,5))print(input.shape)class Tudui(nn.Module):    def __init__(self):        super(Tudui,self).__init__()        self.maxpool1 = MaxPool2d(kernel_size=3,ceil_mode = True)    def forward(self,input):        output = self.maxpool1(input)        return  outputtudui = Tudui()output = tudui(input)print(output)writer = SummaryWriter("logs_maxpool")step = 0for data in dataloader:    imgs,targets = data    writer.add_images("input",imgs,step)    output=tudui(imgs)    writer.add_images("output",output,step)    step = step+1writer.close()