Python 3.x Pytorch:ValueError:预期输入批次大小(32)与目标批次大小(64)匹配
尝试在MNIST数据集上运行CNN示例,批大小=64,通道=1,n_h=28,n_w=28,n_iters=1000。程序运行前500次迭代,然后给出上述误差。 论坛上已经讨论了相同的主题,例如: 而且,它们都不能帮助我识别以下代码中的错误:Python 3.x Pytorch:ValueError:预期输入批次大小(32)与目标批次大小(64)匹配,python-3.x,conv-neural-network,pytorch,Python 3.x,Conv Neural Network,Pytorch,尝试在MNIST数据集上运行CNN示例,批大小=64,通道=1,n_h=28,n_w=28,n_iters=1000。程序运行前500次迭代,然后给出上述误差。 论坛上已经讨论了相同的主题,例如: 而且,它们都不能帮助我识别以下代码中的错误: class CNN_MNIST(nn.Module): def __init__(self): super(CNN_MNIST,self).__init__() # convolution layer 1 self.cnn1 =
class CNN_MNIST(nn.Module):
def __init__(self):
super(CNN_MNIST,self).__init__()
# convolution layer 1
self.cnn1 = nn.Conv2d(in_channels=1, out_channels= 32, kernel_size=5,
stride=1,padding=2)
# ReLU activation
self.relu1 = nn.ReLU()
# maxpool 1
self.maxpool1 = nn.MaxPool2d(kernel_size=2,stride=2)
# convolution 2
self.cnn2 = nn.Conv2d(in_channels=32, out_channels=64, kernel_size=5,
stride=1,padding=2)
# ReLU activation
self.relu2 = nn.ReLU()
# maxpool 2
self.maxpool2 = nn.MaxPool2d(kernel_size=2,stride=2)
# fully connected 1
self.fc1 = nn.Linear(7*7*64,1000)
# fully connected 2
self.fc2 = nn.Linear(1000,10)
def forward(self,x):
# convolution 1
out = self.cnn1(x)
# activation function
out = self.relu1(out)
# maxpool 1
out = self.maxpool1(out)
# convolution 2
out = self.cnn2(out)
# activation function
out = self.relu2(out)
# maxpool 2
out = self.maxpool2(out)
# flatten the output
out = out.view(out.size(0),-1)
# fully connected layers
out = self.fc1(out)
out = self.fc2(out)
return out
# model trainning
count = 0
loss_list = []
iteration_list = []
accuracy_list = []
for epoch in range(int(n_epochs)):
for i, (image,labels) in enumerate(train_loader):
train = Variable(image)
labels = Variable(labels)
# clear gradient
optimizer.zero_grad()
# forward propagation
output = cnn_model(train)
# calculate softmax and cross entropy loss
loss = error(output,label)
# calculate gradients
loss.backward()
# update the optimizer
optimizer.step()
count += 1
if count % 50 ==0:
# calculate the accuracy
correct = 0
total = 0
# iterate through the test data
for image, labels in test_loader:
test = Variable(image)
# forward propagation
output = cnn_model(test)
# get prediction
predict = torch.max(output.data,1)[1]
# total number of labels
total += len(labels)
# correct prediction
correct += (predict==labels).sum()
# accuracy
accuracy = 100*correct/float(total)
# store loss, number of iteration, and accuracy
loss_list.append(loss.data)
iteration_list.append(count)
accuracy_list.append(accuracy)
# print loss and accurcay as the algorithm progresses
if count % 500 ==0:
print('Iteration :{} Loss :{} Accuracy :
{}'.format(count,loss.item(),accuracy))
错误如下:
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-19-9e93a242961b> in <module>
18
19 # calculate softmax and cross entropy loss
---> 20 loss = error(output,label)
21
22 # calculate gradients
~\Anaconda3\lib\site-packages\torch\nn\modules\module.py in __call__(self, *input, **kwargs)
545 result = self._slow_forward(*input, **kwargs)
546 else:
--> 547 result = self.forward(*input, **kwargs)
548 for hook in self._forward_hooks.values():
549 hook_result = hook(self, input, result)
~\Anaconda3\lib\site-packages\torch\nn\modules\loss.py in forward(self, input, target)
914 def forward(self, input, target):
915 return F.cross_entropy(input, target, weight=self.weight,
--> 916 ignore_index=self.ignore_index, reduction=self.reduction)
917
918
~\Anaconda3\lib\site-packages\torch\nn\functional.py in cross_entropy(input, target, weight, size_average, ignore_index, reduce, reduction)
1993 if size_average is not None or reduce is not None:
1994 reduction = _Reduction.legacy_get_string(size_average, reduce)
-> 1995 return nll_loss(log_softmax(input, 1), target, weight, None, ignore_index, None, reduction)
1996
1997
~\Anaconda3\lib\site-packages\torch\nn\functional.py in nll_loss(input, target, weight, size_average, ignore_index, reduce, reduction)
1820 if input.size(0) != target.size(0):
1821 raise ValueError('Expected input batch_size ({}) to match target batch_size ({}).'
-> 1822 .format(input.size(0), target.size(0)))
1823 if dim == 2:
1824 ret = torch._C._nn.nll_loss(input, target, weight, _Reduction.get_enum(reduction), ignore_index)
ValueError: Expected input batch_size (32) to match target batch_size (64).
---------------------------------------------------------------------------
ValueError回溯(最近一次调用上次)
在里面
18
19#计算softmax和交叉熵损失
--->20损失=错误(输出、标签)
21
22#计算坡度
~\Anaconda3\lib\site packages\torch\nn\modules\module.py在调用中(self,*input,**kwargs)
545结果=self.\u slow\u forward(*输入,**kwargs)
546其他:
-->547结果=自我转发(*输入,**kwargs)
548用于钩住自身。\u向前\u钩住.values():
549钩子结果=钩子(自身、输入、结果)
~\Anaconda3\lib\site packages\torch\nn\modules\loss.py前进(自身、输入、目标)
914 def前进(自身、输入、目标):
915返回F.交叉熵(输入,目标,重量=自身重量,
-->916忽略索引=自我。忽略索引,减少=自我。减少)
917
918
交叉熵中的~\Anaconda3\lib\site packages\torch\nn\functional.py(输入、目标、权重、大小平均值、忽略索引、减少、减少)
1993如果尺寸_平均值不是无或减少值不是无:
1994 reduce=\u reduce.legacy\u get\u字符串(大小\u平均值,reduce)
->1995返回nll_损失(log_softmax(输入,1),目标,重量,无,忽略指数,无,减少)
1996
1997
nll\U损耗中的~\Anaconda3\lib\site packages\torch\nn\functional.py(输入、目标、重量、平均尺寸、忽略索引、减少、减少)
1820如果输入。大小(0)!=目标。大小(0):
1821 raise VALUERROR('预期的输入批次大小({})与目标批次大小({})匹配。'
->1822.格式(input.size(0)、target.size(0)))
1823如果尺寸=2:
1824 ret=torch.\u C.\u nn.nll\u损失(输入、目标、重量、减少量。获取枚举(减少量),忽略索引)
ValueError:预期输入批次大小(32)与目标批次大小(64)匹配。
您为您的损失提供了错误的目标:
loss=错误(输出、标签)
当你的加载器给你
枚举(列车装载机)中的i(图像、标签)的:
列车=变量(图)
标签=变量(标签)
因此,您从加载程序中获得了一个变量名labels
(带s
),但您将label
(无s
)添加到您的损失中
批量大小是您最不担心的