C++ 以CSV格式写入特征向量xd

我正在尝试将一个Eigen:：VectorXd写入CSV文件。向量来自一行特征：：矩阵XXD。我的职能定义如下：

void writeMatrixToCSVwithID(fs::path path, VectorXd row, unsigned long int row_id){
    const static IOFormat CSVFormat(StreamPrecision, DontAlignCols, ", ", "\n");
    ofstream file(path.c_str(), std::ofstream::out | std::ofstream::app);
    row.resize(1, row.size());
    file << row_id << ", " << row.format(CSVFormat) << std::endl;
    file.close();
}

预期产出为：

11, 0.247795, 0.327012, 0.502336, 0.569316, 0.705254
12, 0.247795, 0.327012, 0.502336, 0.569316, 0.705254

---

我需要更改什么？

错误的原因是Eigen将VectorXd作为列输出。rowid返回块，该块似乎将行或列提取作为列输出

因此，我不再传递VectorXd行，而是将该行作为MatrixXd传递。IOFormat对象是用行分隔符“，”初始化的

void writeMatrixToCSVwithID(fs::path path, MatrixXd row, unsigned long int row_id){
    const static IOFormat CSVFormat(StreamPrecision, DontAlignCols, ", ", ", ");
    ofstream file(path.c_str(), std::ofstream::app);
    row.resize(1, row.size()); // Making sure that we are dealing with a row.
    file << row_id << ", " << row.format(CSVFormat) << std::endl;
    file.close();
}

这将生成所需的行输出

void writeMatrixToCSVwithID(fs::path path, MatrixXd row, unsigned long int row_id){
    const static IOFormat CSVFormat(StreamPrecision, DontAlignCols, ", ", ", ");
    ofstream file(path.c_str(), std::ofstream::app);
    row.resize(1, row.size()); // Making sure that we are dealing with a row.
    file << row_id << ", " << row.format(CSVFormat) << std::endl;
    file.close();
}