"+d3.format("d")(sample_nb));};

    const rects = container
	  .selectAll(".bar")
   	  .data(hist)
	  .enter();

    rects.append("rect")
	.attr("class", "bar")
	.attr("x", (v, i) => xscale(i*barwidth+min))
	.attr("width", (v, i) => xscale(barwidth)-xscale(0))
	.attr("y", (v, i) => yscale(v))
	.attr("height", (v, i) => innerH-yscale(v))
	.on("mouseover", print_value)
        .on("mouseout", () => d3.selectAll("#tt2").transition().duration("50").remove());

    function update_hist(nbarwidth) {
	//compute 