chart = {
const svg = d3.select(DOM.svg(width, height));
const defs = svg.append("defs");
const linearGradient = defs.append("linearGradient")
.attr("id", "linear");
linearGradient
.attr("x1", "0%")
.attr("y1", "0%")
.attr("x2", "0%")
.attr("y2", "100%");
linearGradient.append("stop")
.attr("offset", "0%")
.attr("stop-color", color1value);
linearGradient.append("stop")
.attr("offset", "100%")
.attr("stop-color", color2value);
svg.append("g")
.call(xAxis);
svg.append("g")
.call(yAxis);
svg.append("path")
.datum(data)
.attr("fill", "none")
.attr("stroke", "url(#linear)")
.attr("stroke-width", 2)
.attr("stroke-linejoin", "round")
.attr("stroke-linecap", "round")
.attr("d", line);
return svg.node();
}