javascript - Change the shape of the edges in D3 -

i have graph uses dagre layout , looks this:

what trying change shape of edges can in zigzag form one:

i have function:

function shape_edges(d) {   return "m" + d.source.y + "," + d.source.x     + "h" + (d.source.y + (d.target.y-d.source.y)/2)     + "v" + d.target.x      + "h" + d.target.y; } 

which, little bit of change can give me shape want.

the problem not sure how use function affect edges.

i creating edges following way:

for (i=0; i<relations.length; i++) {     g.setedge(relations[i][0],relations[i][1], {     arrowheadstyle: "fill: #000",     lineinterpolate: 'linear'       }); } 

i have read lineinterpolate can accept function haven't been able apply shape_edges function it.

can show me how apply desired function can affect edges, or @ least point me in right direction because have been stuck quite time?