yAxis = g => g
.attr("transform", `translate(${margin.left},0)`)
.call(d3.axisLeft(y)
.ticks(null, x => +x.toFixed(6) + "×"))
.call(g => g.selectAll(".tick line").clone()
.attr("stroke-opacity", d => d === 1 ? null : 0.2)
.attr("x2", width - margin.left - margin.right))
.call(g => g.select(".domain").remove())