onnx_resnet50.ipynb : "Unknown operation: Gather"

[ArnaudWald]

Hello,

I'm running the onnx-ngraph example notebook with the resnet pre-trained model here.

At the 3rd cell i get an error when running models = import_onnx_file('resnet.onnx')

Here is the full error :

ONNX `ai.onnx` opset version 9 is not supported. Falling back to latest supported version: 7

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
/usr/local/lib/python3.6/site-packages/ngraph_onnx/onnx_importer/ops_bridge/__init__.py in make_ng_nodes(node_factory, onnx_node)
     39     try:
---> 40         ng_node_factory_function = getattr(node_factory, op_type)
     41     except AttributeError:

AttributeError: module 'ngraph_onnx.onnx_importer.ops_bridge.opset_latest' has no attribute 'Gather'

During handling of the above exception, another exception occurred:

NotImplementedError                       Traceback (most recent call last)
<ipython-input-7-67b1a5109ac6> in <module>
      2 
      3 # Import the ONNX file
----> 4 models = import_onnx_file('resnet.onnx')
      5 
      6 # Create an nGraph runtime environment

/usr/local/lib/python3.6/site-packages/ngraph_onnx/onnx_importer/importer.py in import_onnx_file(filename)
     63     """
     64     onnx_protobuf = onnx.load(filename)
---> 65     return import_onnx_model(onnx_protobuf)

/usr/local/lib/python3.6/site-packages/ngraph_onnx/onnx_importer/importer.py in import_onnx_model(onnx_protobuf)
     51     :return: list of dicts representing ngraph Ops and their inputs
     52     """
---> 53     model = ModelWrapper(onnx_protobuf)
     54     return model.graph.get_ng_model()
     55 

/usr/local/lib/python3.6/site-packages/ngraph_onnx/onnx_importer/model_wrappers.py in __init__(self, model_proto)
     68 
     69         self.node_factory = get_node_factory(opset_version=ai_onnx_opset_version)
---> 70         self.graph = GraphWrapper(model_proto.graph, self)
     71         super(ModelWrapper, self).__init__(model_proto, self.graph)
     72 

/usr/local/lib/python3.6/site-packages/ngraph_onnx/onnx_importer/model_wrappers.py in __init__(self, onnx_proto_instance, model)
     89                             for initializer in self._proto.initializer]
     90         self._initialize_ng_tensors()
---> 91         self._initialize_ng_nodes()
     92 
     93     @lru_cache(maxsize=512)

/usr/local/lib/python3.6/site-packages/ngraph_onnx/onnx_importer/model_wrappers.py in _initialize_ng_nodes(self)
    138         """Create and cache ngraph Op nodes for all operation nodes in the ONNX graph."""
    139         for node in self.node:
--> 140             node.get_ng_nodes_dict()
    141 
    142     def get_input_names(self):  # type: () -> List[str]

/usr/local/lib/python3.6/site-packages/ngraph_onnx/onnx_importer/model_wrappers.py in get_ng_nodes_dict(self)
    314 
    315         output_node_names = self._proto.output
--> 316         output_nodes = make_ng_nodes(self._graph.model.node_factory, self)
    317         for output_name, node in zip(output_node_names, output_nodes):
    318             # Node name equals to unique name only when it just has been created above.

/usr/local/lib/python3.6/site-packages/ngraph_onnx/onnx_importer/ops_bridge/__init__.py in make_ng_nodes(node_factory, onnx_node)
     40         ng_node_factory_function = getattr(node_factory, op_type)
     41     except AttributeError:
---> 42         raise NotImplementedError('Unknown operation: %s', op_type)
     43 
     44     ng_inputs = onnx_node.get_ng_inputs()

NotImplementedError: ('Unknown operation: %s', 'Gather')

I'm running python 3.6, latest versions of onnx, ngraph and ngraph_onnx built from source on Ubuntu 16.04. The example with ngraph-onnx here works fine.

Any ideas where that could come from ? Is the tutorial up-to-date ?

[ukclivecox]

I think the libraries needed at present are

• torch==0.4.0
• torchvision==0.2.1

There may need to be some work to update to latest torch.

[ukclivecox]

The problem is ngraph-onnx doesn't support Gather at present. So Torch 1.0.0 must have changed how it exports the ResNet model compared to 0.4.0 and added the Gather operation for some reason.

[ukclivecox]

@DuanraDlaw We have merged #386 If you can test and give us feedback. Thanks!

[ukclivecox]

Closing fixed. Please reopen if issue.