xAxis2 = g =>
g
.attr('transform', `translate(0, ${height - margin.bottom})`)
.call(d3.axisBottom(x2).ticks(20))
.call(g => g.select(".domain").remove())
.call(g =>
g
.append("text")
.attr("x", width)
.attr("y", margin.bottom - 25)
.attr("fill", "currentColor")
.attr("text-anchor", "end")
.text("Previous time between waves (s) →")
)