Eigen3:写出稀疏矩阵

Question

我使用以下代码在Eigen3中创建了一个稀疏矩阵：

#include <eigen3/Eigen/Sparse>
#include <eigen3/unsupported/Eigen/src/SparseExtra/MarketIO.h>
#include <vector>

using SpMatrix = Eigen::SparseMatrix<double>;
using Eigen::SparseMatrix;
using S = Eigen::Triplet<double>;
using namespace std;
using AdjacenyMatrix = SpMatrix;

int main() {

    vector <S> nonzero_compenents;
    AdjacenyMatrix am(10, 10);
    nonzero_compenents.push_back(move(S(1, 1, 1.0)));

    am.setFromTriplets(nonzero_compenents.begin(), nonzero_compenents.end());

    bool s = saveMarket(am, "/home/morris/Schreibtisch/sparse_matrices");

    return 0;

}

不幸的是，代码无法编译。MarketIO.h中似乎有问题

In file included from /home/morris/sparse/main.cpp:2:0:
/usr/include/eigen3/unsupported/Eigen/src/SparseExtra/MarketIO.h: In function ‘void Eigen::internal::PutMatrixElt(Scalar, int, int, std::ofstream&)’:
/usr/include/eigen3/unsupported/Eigen/src/SparseExtra/MarketIO.h:87:9: error: no match for ‘operator<<’ (operand types are ‘std::ofstream {aka std::basic_ofstream<char>}’ and ‘int’)
     out << row << " "<< col << " " << value << "\n";
         ^

..。有什么建议吗？

Answer 1

正如@ggael所说:不要包含单独的文件，而是包含它们的模块/目录。请注意，在这种情况下，您还需要从路径中删除src。

之前：

#include <eigen3/unsupported/Eigen/src/SparseExtra/MarketIO.h>

现在：

#include <eigen3/unsupported/Eigen/SparseExtra>

完整代码：

#include <eigen3/Eigen/Sparse>
#include <eigen3/unsupported/Eigen/SparseExtra>
#include <vector>

using SpMatrix = Eigen::SparseMatrix<double>;
using Eigen::SparseMatrix;
using S = Eigen::Triplet<double>;
using namespace std;
using AdjacenyMatrix = SpMatrix;

int main() {

    vector <S> nonzero_compenents;
    AdjacenyMatrix am(10, 10);
    nonzero_compenents.push_back(move(S(1, 1, 1.0)));

    am.setFromTriplets(nonzero_compenents.begin(), nonzero_compenents.end());

    bool s = saveMarket(am, "/home/morris/Schreibtisch/sparse_matrices");

    return 0;

}

现在，它应该使用例如

g++ -std=c++11 mycode.cc

Answer 2

使用

#include <fstream>
#include <Eigen/Sparse>
#include <unsupported/Eigen/SparseExtra>

而不是

#include <eigen3/Eigen/Sparse>
#include <eigen3/unsupported/Eigen/src/SparseExtra/MarketIO.h>

代码将进行编译

注意：：#include <eigen3/unsupported/Eigen/SparseExtra>无法编译