from paddle import nn
import paddle

pre = paddle.to_tensor([[ [[1.4146, 0.1446],[1.8990, -1.1429]],[[0.9828, -1.8893],[-1.5256, -1.8724]],[[-1.2521, 1.8987],[-0.2531, -0.1878]]]],'float32')
mask1 = paddle.to_tensor([[[1,2],[2,0]]])
ce_loss = nn.CrossEntropyLoss()
ce_loss(pre,mask1)

pre 维度 [1,3,2,2]

mask1 维度[1,2,2]

用Torch 得到的结果是1.2123

用paddle得到的错误是

----> 3 ce_loss(pre,mask1)

/opt/conda/envs/python35-paddle120-env/lib/python3.7/site-packages/paddle/fluid/dygraph/layers.py in __call__(self, *inputs, **kwargs)
    915 
    916     def __call__(self, *inputs, **kwargs):
--> 917         return self._dygraph_call_func(*inputs, **kwargs)
    918 
    919     def forward(self, *inputs, **kwargs):

/opt/conda/envs/python35-paddle120-env/lib/python3.7/site-packages/paddle/fluid/dygraph/layers.py in _dygraph_call_func(self, *inputs, **kwargs)
    905             self._built = True
    906 
--> 907         outputs = self.forward(*inputs, **kwargs)
    908 
    909         for forward_post_hook in self._forward_post_hooks.values():

/opt/conda/envs/python35-paddle120-env/lib/python3.7/site-packages/paddle/nn/layer/loss.py in forward(self, input, label)
    404             axis=self.axis,
    405             use_softmax=self.use_softmax,
--> 406             name=self.name)
    407 
    408         return ret

/opt/conda/envs/python35-paddle120-env/lib/python3.7/site-packages/paddle/nn/functional/loss.py in cross_entropy(input, label, weight, ignore_index, reduction, soft_label, axis, use_softmax, name)
   1660             if label_max >= input.shape[axis]:
   1661                 raise ValueError("label should not out of bound, but got{}".
-> 1662                                  format(label_max))
   1663 
   1664         _, out = _C_ops.softmax_with_cross_entropy(

ValueError: label should not out of bound, but gotTensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
       [2])