pytorch转onnx问题

Fail to export the model in PyTorch

https://github.com/onnx/tutorials/blob/master/tutorials/PytorchAddExportSupport.md#fail-to-export-the-model-in-pytorch

1. RuntimeError: ONNX export failed: Couldn't export operator aten::rsqrt

2. RuntimeError: ONNX export failed: Couldn't export operator aten::reshape

原因：pytorch-1.0.1不支持reshape操作

解决：~/anaconda3/envs/py36/lib/python3.6/site-packages/torch/onnx/symbolic.py

在该文件中添加代码

def reshape(g, self, shape):
    return view(g, self, shape)
 
def reshape_as(g, self, other):
    shape = g.op('Shape', other)
    return reshape(g, self, shape)

3. ONNX export failed on ATen operator group_norm because torch.onnx.symbolic.group_norm does not exist

解决：~/anaconda3/envs/py36/lib/python3.6/site-packages/torch/onnx/symbolic.py

@parse_args('v', 'i', 'v', 'v', 'f', 'i')
def group_norm(g, input, num_groups, weight, bias, eps, cudnn_enabled):
    return g.op("ATen", input, weight, bias, num_groups_i=num_groups,
                eps_f=eps, cudnn_enabled_i=cudnn_enabled, operator_s="group_norm")