Hi all,
I am finetuning the resnet50 model as follows:
classifier = resnet50(pretrained=False)
classifier.fc = nn.Linear(2048, 256)
for param in classifier.parameters():     #for NOT freezing model
param.requires_grad = True
classifier_criterion = nn.CrossEntropyLoss()  # loss function of classifier
classifier_criterion.requires_grad=True
classifier_optimizer = optim.SGD(classifier.parameters(), lr=1e-2, momentum=0.9) # classifier optimizer
input_classifier = torch.FloatTensor(opt.batchSize, opt.output_nc,256,256)
classifier_output = torch.FloatTensor(256)
classifier_criterion=classifier_criterion.cuda()
classifier_output=Variable(classifier_output,requires_grad=True)
img is a image of dimension 1x3x256x256
input_classifier = transform_classifier(img)
classifier_optimizer.zero_grad()
classifier_output.data = classifier(input_classifier)
#label.requires_grad=True
#classifier_output.requires_grad=True
classifier_loss = classifier_criterion(classifier_output, label)
classifier_loss.requires_grad = True
classifier_loss.backward()  # this loss has to backproped to G as well
classifier_optimizer.step()    # Does the update
NOW, i AM GETTING THE FOLLOWING ERROR,
Traceback (most recent call last):
File “train_finetune_cscrv.py”, line 285, in 
train(epoch)
File “train_finetune_cscrv.py”, line 203, in train
classifier_output.data = classifier(input_classifier)
File “/home/iab/anaconda2/envs/pytorch/lib/python2.7/site-packages/torch/nn/modules/module.py”, line 224, in call
result = self.forward(*input, **kwargs)
File “build/bdist.linux-x86_64/egg/torchvision/models/resnet.py”, line 139, in forward
File “/home/iab/anaconda2/envs/pytorch/lib/python2.7/site-packages/torch/nn/modules/module.py”, line 224, in call
result = self.forward(*input, **kwargs)
File “/home/iab/anaconda2/envs/pytorch/lib/python2.7/site-packages/torch/nn/modules/conv.py”, line 254, in forward
self.padding, self.dilation, self.groups)
File “/home/iab/anaconda2/envs/pytorch/lib/python2.7/site-packages/torch/nn/functional.py”, line 52, in conv2d
return f(input, weight, bias)
TypeError: argument 0 is not a Variable
#---------------end------------------------------
I have tried a lot but I am not being able ti fix it. On this thread NN Tutorial: Argument 0 is not a Variable they are saying to update the torch.
As mentioned in the tutorial when I making the input to the classifier as a variable as follows:
input_classifier=Variable(input_classifier)
I AM GETTING THE FOLLOWING ERROR:
File “train_finetune_cscrv.py”, line 285, in 
train(epoch)
File “train_finetune_cscrv.py”, line 203, in train
classifier_output.data = classifier(input_classifier)
RuntimeError: Variable data has to be a tensor, but got Variable
@Soumith_Chintala  We need your expertise here.
KINDLY HELP !!!