Hi all,

I am very new in Eigen and C++ but I need it urgently for my research work. In one part of my code I need to multiply a Sparse Matrix with a vector and this is not working

Here my step with a small test model:

1) I created a very simple sparse Matrix (3X3)

SparseMatrix<int> SpNM2(3,3);
SpNM2.coeffRef(i,j)=(i+(j*i));

Here the Sparse:
0 0 0
1 2 3
2 4 6

I created a Vector
VectorXd v(3);

And then test:

SpNM*v;

And I got the next message:
Error 7 error C2039: 'Scalar' : is not a member of 'Eigen::internal::traits<T>' c:\eigen2\eigen\src\core\densebase.h 48 Eigen32

Then I though I should try with a Sparse Vector better...,

SparseVector<int> v(ne);
SpNM*v;

And I got this.

Error 3 error C2039: 'reserve' : is not a member of 'Eigen::Matrix<_Scalar,_Rows,_Cols>' c:\eigen2\eigen\src\sparsecore\sparsesparseproductwithpruning.h 65 Eigen32


I am sure I miss something very big!! but I cannot find it in the tutorial.

Please any help would very appreciate

Thanks!!!
Robin

I doubt you can multiply a SparseMatrix<int> (where all the entries are an int) with a MatrixXd (where all the entries are a double), so that may explain the first error.

For the second error, I don't know. It would help if you could post the whole program (try to make it as small as possible).

Fantastic!! It seems that with all in double is working fine

I will prepare a small clean code to illustrate better the second problem ( Sparse Matrix * Sparse Vector).

I move a bench of new question as a new topic (viewtopic.php?f=74&t=106957) if you have a chance

Thanks again you save my day!

Cheers,
Robin