cout<< "Row major input:"<< endl<< M3<< "\n";Map< RowMajorMatrixXf, 0, Stride< Dynamic, 3 > > M4(M3.data(), M3.rows(),(M3.cols()+2)/3, Stride< Dynamic, 3 >(M3.outerStride(), 3))
cout<< "Column major input:"<< endl<< M1<< "\n";Map< MatrixXf, 0, OuterStride<> > M2(M1.data(), M1.rows(),(M1.cols()+2)/3, OuterStride<>(M1.outerStride() *3))