如何在Eigen中以MarketIO格式保存Eigen :: DiagonalMatrix？

Question

Using Eigen 3.2.1 , I am trying to save an Eigen::DiagonalMatrix in MarketIO format as below:

#include <Eigen/Sparse>
#include <Unsupported/Eigen/SparseExtra>
using namespace Eigen;
...

size_t n = XX;
DiagonalMatrix<num_t, Dynamic> W(n);
...
saveMarket(W, "W.txt"); // error propagates from here

However, I am getting the following error:

MarketIO.h|236|error: 'const class Eigen::DiagonalMatrix<double, -1>' has no
member named 'nonZeros'

What is the problem here? Is this implemented at all for Diagonal Matrices ?

Thanks in advance for any help.

Answer 1

Okay! The only solution for now with minimal effort is to use the following:

saveMarketVector(W.diagonal(), "W.txt");