const xScale=d3.scalePoint()
                    .domain(dates) // dates is a array of date objects
                    .range([0,w])

const xAxis=d3.axisBottom(xScale);

svg.append("g")
            .attr("class","axis")
            .attr(`transform`,`translate(0,${h})`)
            .call(xAxis)
             .ticks(4) // It does not work  in this code