chart = {
const width = 928;
const height = 600;
const marginTop = 20;
const marginRight = 30;
const marginBottom = 30;
const marginLeft = 40;
const x = d3.scaleUtc()
.domain(d3.extent(sftemp, d => d.date))
.range([marginLeft, width - marginRight]);
const y = d3.scaleLinear()
.domain([d3.min(sftemp, d => d.low), d3.max(sftemp, d => d.high)]).nice(10)
.range([height - marginBottom, marginTop]);
const area = d3.area()
.curve(d3.curveStep)
.x(d => x(d.date))
.y0(d => y(d.low))
.y1(d => y(d.high));
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [0, 0, width, height])
.attr("style", "max-width: 100%; height: auto; height: intrinsic;");
svg.append("path")
.datum(sftemp)
.attr("fill", "steelblue")
.attr("d", area);
svg.append("g")
.attr("transform", `translate(0,${height - marginBottom})`)
.call(d3.axisBottom(x).ticks(width / 80).tickSizeOuter(0))
.call(g => g.select(".domain").remove());
svg.append("g")
.attr("transform", `translate(${marginLeft},0)`)
.call(d3.axisLeft(y))
.call(g => g.select(".domain").remove())
.call(g => g.selectAll(".tick line").clone()
.attr("x2", width - marginLeft - marginRight)
.attr("stroke-opacity", 0.1))
.call(g => g.append("text")
.attr("x", -marginLeft)
.attr("y", 10)
.attr("fill", "currentColor")
.attr("text-anchor", "start")
.text("↑ Temperature (°F)"));
return svg.node();
}