RuntimeError: The size of tensor a (128) must match the size of tensor b (3) at non-singleton dimension 1

这个 RuntimeError 错误通常发生在两个张量的维度不匹配的时候。在这种情况下，张量 a 的大小为 128，而张量 b 的大小为 3，这导致它们在非单一维度 1 上大小不匹配。您需要检查您的代码，确定什么地方存在大小不匹配的问题，并将它们纠正。您可以使用 PyTorch 中的 view、reshape 或者 transpose 等函数来改变张量的大小和维度，使其与您需要的操作相匹配。 它可能还需要检查您的数据是否被误用或者格式不正确。

相关问题

RuntimeError: The size of tensor a (84) must match the size of tensor b (56) at non-singleton dimension 3

引用\[1\]和\[2\]提到了类似的错误信息，即"RuntimeError: The size of tensor a (4) must match the size of tensor b (2) at non-singleton dimension 1"和"RuntimeError: The size of tensor a (4) must match the size of tensor b (3) at non-singleton dimension 0"。这些错误通常是由于维度信息不匹配导致的。引用\[2\]中提供了一个解决办法，即将图像转换为RGB格式。因此，对于你的问题"RuntimeError: The size of tensor a (84) must match the size of tensor b (56) at non-singleton dimension 3"，你可以尝试将图像转换为RGB格式来解决这个问题。
#### 引用[.reference_title]
- *1* [RuntimeError: The size of tensor a (4) must match the size of tensor b (2) at non-singleton dimensio](https://blog.csdn.net/weixin_44337238/article/details/124293003)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v91^control_2,239^v3^insert_chatgpt"}} ] [.reference_item]
- *2* [报错解决——RuntimeError: The size of tensor a (4) must match the size of tensor b (3) at non-...](https://blog.csdn.net/Williamcsj/article/details/125746752)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v91^control_2,239^v3^insert_chatgpt"}} ] [.reference_item]
- *3* [RuntimeError: The size of tensor a (4) must match the size of tensor b (3) at non-singleton dimensio](https://blog.csdn.net/weixin_46135327/article/details/130805823)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v91^control_2,239^v3^insert_chatgpt"}} ] [.reference_item]
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RuntimeError: The size of tensor a (128) must match the size of tensor b (122) at non-singleton dimension 3

这个报错的原因是由于在计算过程中，两个张量的尺寸不匹配导致的。根据引用的描述，这个问题可能是在读取图片时出现的。要解决这个问题，可以尝试将图片转换为RGB格式。另外，根据引用的建议，在DataLoader函数中添加参数"drop_last=False"也可能解决这个问题。具体地，你可以像下面这样修改代码：

dataloader = DataLoader(ImageDataset(opt.dataroot, transforms_=transforms_, unaligned=True), batch_size=opt.batchSize, shuffle=True, num_workers=opt.n_cpu, drop_last=False)

通过保持batch的尺寸不变来避免尺寸不匹配的问题。希望这个解决方案能帮到你！<span class="em">1</span><span class="em">2</span>
#### 引用[.reference_title]
- *1* [RuntimeError: The size of tensor a (4) must match the size of tensor b (3) at non-singleton dimensio](https://blog.csdn.net/weixin_46135327/article/details/130805823)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT3_1"}}] [.reference_item style="max-width: 50%"]
- *2* [RuntimeError: The size of tensor a (8) must match the size of tensor b (7) at non-singleton dimensio](https://blog.csdn.net/m0_46368408/article/details/131231563)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT3_1"}}] [.reference_item style="max-width: 50%"]
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