[eigen] How to create a Matrix<...> without copying data ?

[<vincent.lejeune@xxxxxxxxxx>]

Hi,



I have a matrix stored as a double* in columnsmajor format.

I would like to compute the LU factorisation of a part of the matrix (that

is, not the whole matrix, just a sub square of it) inplace, ie I do not

want to copy data to an temporary buffer.



Is it possible using Eigen ? I saw that PartialPivLU class copy input

matrix when constructed...



Thx,

Vincent