incidence matrix with respect to an orientation

Let $G$ be a finite graph with $n$ vertices, $\{v_1,\mathrm{\dots },v_n\}$and $m$ edges, $\{e_1,\mathrm{\dots },e_m\}$.For each edge $e=(v_i,v_j)$ of $G$ choose one vertexto be the positive end and the other to be the negative end. In this way,we assign an orientation to $G$. The of $G$ with respect an orientation is an $n\times m$ matrix$D=(d_{ij})$where