Can anyone tell me what is a way to create an iterator through a row/column of an eigen matrix?

Does A.row(i).begin() work? The InnerIterator method seems to work only for sparse matrices.

Thanks in advance

For a column of a column-major matrix, you can use: A.col(j).data(), A.col(j).data()+A.rows() as begin/end pair. For a row, it is more tricky because you have to use A.outerStride() as the increment.

Hi,

Can you please tell me the outerstride usage? Thanks

A.outerStride() is the number of elements to skip from column to the next one. So you can loop over a row as:


for(double *it=A.row(i).data(); it<A.row(i).data()+A.size(); it+=A.outerSrtride()) {
*it ;
}