onnx-go-开放神经网络交换 （ONNX） 的 Go 接口

  [](https://github.com/avelino/awesome-go#machine-learning) [](https://godoc.org/github.com/owulveryck/onnx-go) [](https://goreportcard.com/report/github.com/owulveryck/onnx-go) [](https://travis-ci.com/owulveryck/onnx-go) [](https://codecov.io/gh/owulveryck/onnx-go) This is a Go Interface to [Open Neural Network Exchange (ONNX)](https://onnx.ai/). ## Overview onnx-go contains primitives to decode a onnx binary model into a computation backend, and use it like any other library in your go code. for more information about onnx, please visit [onnx.ai](https://onnx.ai). The implementation of the [the spec of ONNX](https://github.com/onnx/onnx/blob/master/docs/IR.md) is partial on the import, and non-existent for the export. ### Vision statement > For the Go developer who needs to add a machine learning capability to his/her code, > onnx-go is a package that facilitates the use of neural network models (software 2.0) > and unlike any other computation library, this package does not require special skills in data-science. **Warning** The API is experimental and may change. ### Disclaimer [embedmd]:# (RELNOTES.md) ```md This is a new version of the API. The tweaked version of Gorgonia have been removed. It is now compatible with the master branch of Gorgonia. Some operators are not yet available though. A utility has been added in order to run models from the zoo. check the `examples` subdirectory. ``` ## Install Install it via go get ``` go get github.com/owulveryck/onnx-go ``` onnx-go is compatible with [go modules](https://github.com/golang/go/wiki/Modules). ## Example Those examples assumes that you have a pre-trained `model.onnx` file available. You can download pre-trained modles from the [onnx model zoo](https://github.com/onnx/models). ### Very simple example This example does nothing but decoding the graph into a simple backend. Then you can do whatever you want with the generated graph. [embedmd]:# (example_test.go /\/\/ Create/ /model.UnmarshalBinary.*/) ```go // Create a backend receiver backend := simple.NewSimpleGraph() // Create a model and set the execution backend model := onnx.NewModel(backend) // read the onnx model b, _ := ioutil.ReadFile("model.onnx") // Decode it into the model err := model.UnmarshalBinary(b) ``` ### Simple example to run a pre-trained model This example uses [Gorgonia](https://github.com/gorgonia/gorgonia) as a backend. ```go import "github.com/owulveryck/onnx-go/backend/x/gorgonnx" ``` At the present time, Gorgonia does not implement all the operators of ONNX. Therefore, most of the model from the model zoo will not work. Things will go better little by little by adding more operators to the backend. You can find a list of tested examples and a coverage [here](https://github.com/owulveryck/onnx-go/blob/master/backend/x/gorgonnx/ONNX_COVERAGE.md). [embedmd]:# (example_gorgonnx_test.go /func Ex/ /^}/) ```go func Example_gorgonia() { // Create a backend receiver backend := gorgonnx.NewGraph() // Create a model and set the execution backend model := onnx.NewModel(backend) // read the onnx model b, _ := ioutil.ReadFile("model.onnx") // Decode it into the model err := model.UnmarshalBinary(b) if err != nil { log.Fatal(err) } // Set the first input, the number depends of the model model.SetInput(0, input) err = backend.Run() if err != nil { log.Fatal(err) } // Check error output, _ := model.GetOutputTensors() // write the first output to stdout fmt.Println(output[0]) } ``` ### Model zoo In the `examples` subdirectory, you will find a utility to run a model from the zoo, as well as a sample utility to analyze a picture with [Tiny YOLO v2](https://pjreddie.com/darknet/yolov2/) ## Internal ### ONNX protobuf definition The protobuf definition of onnx has is compiled into Go with the classic `protoc` tool. The definition can be found in the `internal` directory. The definition is not exposed to avoid external dependencies to this repo. Indeed, the pb code can change to use a more efficient compiler such as `gogo protobuf` and this change should be transparent to the user of this package. ### Execution backend In order to execute the neural network, you need a backend able to execute a computation graph (_for more information on computation graphs, please read this [blog post](http://gopherdata.io/post/deeplearning_in_go_part_1/)_ This picture represents the mechanism:  onnx-go do not provide any executable backend, but for a reference, a simple backend that builds an information graph is provided as an example (see the `simple` subpackage). Gorgonia is the main target backend of ONNX-Go. #### Backend implementation a backend is basically a Weighted directed graph that can apply on Operation on its nodes. It should fulfill this interface: [embedmd]:# (backend.go /type Backend/ /}/) ```go type Backend interface { OperationCarrier graph.DirectedWeightedBuilder } ``` [embedmd]:# (backend.go /type OperationCarrier/ /}/) ```go type OperationCarrier interface { // ApplyOperation on the graph nodes // graph.Node is an array because it allows to handle multiple output // for example a split operation returns n nodes... ApplyOperation(Operation, ...graph.Node) error } ``` An Operation is represented by its `name` and a map of attributes. For example the Convolution operator as described in the [spec of onnx](https://github.com/onnx/onnx/blob/master/docs/Operators.md#Conv) will be represented like this: [embedmd]:# (conv_example_test.go /convOperator/ /}$/) ```go convOperator := Operation{ Name: "Conv", Attributes: map[string]interface{}{ "auto_pad": "NOTSET", "dilations": []int64{1, 1}, "group": 1, "pads": []int64{1, 1}, "strides": []int64{1, 1}, }, } ``` Besides, operators, a node can carry a value. Values are described as [`tensor.Tensor`](https://godoc.org/gorgonia.org/tensor#Tensor) To carry data, a *`Node`* of the graph should fulfill this interface: [embedmd]:# (node.go /type DataCarrier/ /}/) ```go type DataCarrier interface { SetTensor(t tensor.Tensor) error GetTensor() tensor.Tensor } ``` #### Backend testing onnx-go provides a some utilities to test a backend. Visit the [`testbackend` package](backend/testbackend) for more info. ## Contributing Contributions are welcome. A contribution guide will be eventually written. Meanwhile, you can raise an issue or send a PR. You can also contact me via Twitter or on the gophers' slack (I am @owulveryck on both) This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct. ## Author [Olivier Wulveryck](https://about.me/owulveryck/getstarted) ## License MIT.