my whole error message is: RuntimeError: size mismatch, m1: [64 x 3200], m2: [512 x 1] at C:/w/1/s/windows/pytorch/aten/src\THC/generic/THCTensorMathBlas.cu:290
and my code:
os.makedirs("../../data/mnist", exist_ok=True)
labels_path = 'C:/project/PyTorch-GAN/ulna/train-labels-idx1-ubyte.gz'
images_path = 'C:/project/PyTorch-GAN/ulna/train-images-idx3-ubyte.gz'
label_name = []

with gzip.open(labels_path, 'rb') as lbpath:
    labels = np.frombuffer(lbpath.read(), dtype="int32", offset=8)
with gzip.open(images_path, 'rb') as imgpath:
    images = np.frombuffer(imgpath.read(), dtype="int32", offset=16).reshape(len(labels),70,70,1)

hand_transform2 = transforms.Compose([
                transforms.Resize((70, 70)),
                transforms.Grayscale(1),
                transforms.ToTensor(),
                transforms.Normalize([0.5], [0.5])
                ])

#images=cv2.resize(images, (70, 70),1)
dataset1 = datasets.ImageFolder('C:/project/PyTorch-GAN/ulna/ulna', transform=hand_transform2)


dataloader = torch.utils.data.DataLoader(
    dataset1,
    batch_size=opt.batch_size,
    shuffle=True,
)```

what is the problem?? thank you!