Is there currently an easy way to assign a DiagonalMatrix to the more general SparseMatrix? I'd like to do something like:

Code: Select all

SparseMatrix<double> S;
DiagonalMatrix<double,Dynamic> D;
S = D;

But I get errors like:

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/opt/local/include/eigen3/Eigen/src/SparseCore/SparseMatrixBase.h:44:23: error: no matching member function for call to
      'evalTo'
      other.derived().evalTo(derived());
      ~~~~~~~~~~~~~~~~^~~~~~
/opt/local/include/eigen3/Eigen/src/SparseCore/SparseMatrix.h:739:20: note: in instantiation of function template
      specialization 'Eigen::SparseMatrixBase<Eigen::SparseMatrix<double, 0, int>
      >::operator=<Eigen::DiagonalMatrix<double, -1, -1> >' requested here
    { return Base::operator=(other.derived()); }
                   ^
...:15:5: note: in instantiation of function template specialization
      'Eigen::SparseMatrix<double, 0, int>::operator=<Eigen::DiagonalMatrix<double, -1, -1> >' requested here

This would be helpful for passing DiagonalMatrix variables directly as arguments to functions expecting general SparseMatrices.

This now works with the devel branch through operator= (as in your example) or an explicit ctor.