export default function (parent, x0, y0, x1, y1) {
var nodes = parent.children,
node,
i = -1,
n = nodes.length,
k = parent.value && (x1 - x0) / parent.value;
while (++i < n) {
node = nodes[i], node.y0 = y0, node.y1 = y1;
node.x0 = x0, node.x1 = x0 += node.value * k;
}
}