Ubuntu20.04+vscode的libtorch环境配置(跑起来测试demo)

初学，网上资料五花八门，又多又乱，查了很久资料才跑通，记录一下防止自己老年痴呆…

1.在pytorch官网找到libtorch，下载压缩文件，解压获得源码

官网下载

2.使用pytorch训练模型(前面可以都不看，就看模型怎么保存的)

if __name__ == '__main__':
	# 训练好的模型
    model = torch.load('model/best_model.pth')
    # 必须使用torch.jit.trace来处理模型，第一个参数就是训练好的模型，第二个参数是规定的输入维度！！这里将会对cpp中的输入维度有所限制
    traced_script_module = torch.jit.trace(model, torch.rand(1, 10, 1))
    traced_script_module.save('model/best_model.pt')
    # print(model)
    test()

3.准备好自己用pytorch训练好的模型，设置预先规定好的输入维度信息

#include <torch/script.h>  // One-stop header.
#include <iostream>
#include <memory>

int main() {
  // Deserialize the ScriptModule from a file using torch::jit::load().
  //std::shared_ptr<torch::jit::script::Module> module =
  //          torch::jit::load("E:/HM_DL/torch_test/traced_resnet_model.pt");

  using torch::jit::script::Module;
  Module module =
      torch::jit::load("/home/coshe/PycharmProjects/LSTM_Test/model/best_model.pt");

  std::cout << "ok\n";
  // Create a vector of inputs.
  std::vector<torch::jit::IValue> inputs;
  //在这里构造输入的维度，例如这里之前有规定输入维度为[1, 10, 1]
  inputs.push_back(torch::rand({1, 10, 1}));

  // Execute the model and turn its output into a tensor.
  std::cout << "inputs: " << std::endl;
  std::cout << inputs << std::endl;

  at::Tensor output = module.forward(inputs).toTensor();



  std::cout << output << '\n';
  // while (1)
  //   ;
}

如果有强迫症（比如我）受不了头文件<torch/script.h>爆红,可以在vscode的c_cpp_properties.json中手动写入头文件路径，什么？你找不到？快捷键Ctrl+
p,然后输入一个’>’,回车就是了，然后配置如下

{
    "configurations": [
        {
            "name": "Linux",
            "includePath": [
                "${workspaceFolder}/**",
                "/home/coshe/下载/libtorch/include"
            ],
            "defines": [],
            "compilerPath": "/usr/bin/clang",
            "cStandard": "c11",
            "cppStandard": "c++14",
            "intelliSenseMode": "linux-clang-x64"
        }
    ],
    "version": 4
}

就把"includePath里面加一个libtorch的include路径就ok了"

4.CMakeLists.txt的编写

cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
project(example)

# 改成自己的相应的目录
set(Torch_DIR /home/coshe/下载/libtorch/share/cmake/Torch)

find_package(Torch REQUIRED)

# message(STATUS "Pytorch status:")
# message(STATUS "    libraries: ${TORCH_LIBRARIES}")
# message(STATUS "OpenCV library status:")
add_executable(example example-app.cpp)

target_link_libraries(example ${TORCH_LIBRARIES})
set_property(TARGET example PROPERTY CXX_STANDARD 14)

然后就是

# 编译
mkdir build && cd ./build
cmake ..
make -j8
# 运行
./example

发现成功了，输出如下：

coshe@coshe-pc:~/文档/torch-cpp/libtorch_test/build$ ./example 
ok
inputs: 
(1,.,.) = 
  0.4012
  0.3990
  0.4569
  0.0698
  0.1218
  0.2944
  0.6884
  0.9574
  0.9151
  0.4877
[ CPUFloatType{1,10,1} ]
 0.9934
[ CPUFloatType{1,1} ]