Environments:
ubuntu 16.04
cuda8.0
python: 3.5.2
pytorch: 1.0.1
torchvision: 0.2.2
Hi guys, when I use torch.onnx.export, I get some problems. The code is just from the  " Example: End-to-end AlexNet from PyTorch to Caffe" (https://pytorch.org/docs/stable/onnx.html?highlight=export#torch.onnx.export 5)
import torch
import torchvision

dummy_input = torch.randn(10, 3, 224, 224, device='cuda')
model = torchvision.models.alexnet(pretrained=True).cuda()
input_names = [ "actual_input_1" ] + [ "learned_%d" % i for i in range(16) ]
output_names = [ "output1" ]

torch.onnx.export(model, dummy_input, "alexnet.onnx", verbose=True, input_names=input_names, output_names=output_names)

Here is the error:
Traceback (most recent call last):
File “pytorch_to_onnx.py”, line 10, in 
torch.onnx.export(model, dummy_input, “alexnet.onnx”, verbose=True)#, input_names=input_names, output_names=output_names)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/init.py”, line 27, in export
return utils.export(*args, **kwargs)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/utils.py”, line 104, in export
operator_export_type=operator_export_type)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/utils.py”, line 281, in _export
example_outputs, propagate)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/utils.py”, line 227, in _model_to_graph
graph = _optimize_graph(graph, operator_export_type)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/utils.py”, line 155, in _optimize_graph
graph = torch._C._jit_pass_onnx(graph, operator_export_type)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/init.py”, line 52, in _run_symbolic_function
return utils._run_symbolic_function(*args, **kwargs)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/utils.py”, line 504, in _run_symbolic_function
return fn(g, *inputs, **attrs)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/symbolic.py”, line 89, in wrapper
return fn(g, *args)
File “/usr/local/lib/python3.5/dist-packages/torch/onnx/symbolic.py”, line 600, in adaptive_avg_pool2d
assert output_size == [1, 1], “Only output_size=[1, 1] is supported”
AssertionError: Only output_size=[1, 1] is supported
By the way, the documents about torch.onnx.export()  are vague. I cannot understand what the arguments input_names and output_names are for?
Any cues would be appreciated!