Using our previous example from enter, we'll continue with updating our lines:

 function update(self, storage, timing) {
  // Update each line
  storage.linePaths.transition().duration(timing)
    .style('opacity', 1)
    .attr('d', storage.line
      .x(function (d) { return self.xScale(new Date(d.x)); })
      .y(function (d) { return self.yScale(d.y); })
    );
}