order eigenvectors

[EsmeraldaRuiz]

Hello, I want to calculate the eigenvectors to get the second smallest one for segmentation using DGESVD.
My problem is that I don´t know if the order is by columns or rows.

I use the lastrow-1 and I move by columns. Should it be correct?.

for(int j=0;j<nodes;j++){
eigenToProject[j] = (float) evec[nodes-2][j];
}

I thought it was like that but when I used arpack it was by columns and as arpack uses lapack
I am a bit confused. becuase I need both.

Thanks !!