Hi,

With Eigen 3.2.7, I try to concatenate (vertical) (vertcat in a great numerical tools) of sparses

A, B sparse and C the result of [A;B]

I try to do something as:
spMatC->middleRows(spMatA->rows(), 0) = *spMatA;
spMatC->middleRows(spMatA->rows(), spMatB->rows()) = *spMatB;

But I have some build errors:
Error 5 error C2039: 'insertBackByOuterInner' : is not a member of 'Eigen::Block<Derived,-1,-1,false>' eigen\eigen\src\SparseCore\SparseMatrixBase.h 227 1 nlsSparse
Error 3 error C2039: 'reserve' : is not a member of 'Eigen::Block<Derived,-1,-1,false>' eigen\eigen\src\SparseCore\SparseMatrixBase.h 220 1 nlsSparse
Error 1 error C2039: 'resize' : is not a member of 'Eigen::Block<Derived,-1,-1,false>' eigen\eigen\src\SparseCore\SparseMatrixBase.h 218 1 nlsSparse
Error 2 error C2039: 'setZero' : is not a member of 'Eigen::Block<Derived,-1,-1,false>' eigen\eigen\src\SparseCore\SparseMatrixBase.h 219 1 nlsSparse
Error 4 error C2039: 'startVec' : is not a member of 'Eigen::Block<Derived,-1,-1,false>' eigen\eigen\src\SparseCore\SparseMatrixBase.h 223 1 nlsSparse

[A,B] works perfectly:
spMatC->middleCols(0, spMatA->cols()) = *spMatA;
spMatC->middleCols(spMatA->cols(), spMatB->cols()) = *spMatB;


Maybe it is not the good way to do ?

Thanks for your help

This is because for sparse matrices, you can only write to consecutive columns (resp. rows) of a column-major (resp. row-major) sparse matrix. It is strange that you don't get an error like not operator= found....