Producing open source analytics and vis @Kitware.
Published
Edited
Mar 31, 2020
md`# US Covid-19`
groupBy = 'total'
cumulative = true
axisX = 'date'
axisY = 'cases'
logScale = false
showPoints = true
filter = d => d.state === 'New York' && d.county === 'Saratoga'
chart = {
const zero = 0.6;
const zeroAxis = 0.4;
const svg = d3
.create('svg')
.attr('class', 'chart')
.attr('viewBox', [0, 0, width, height]);
yield svg.node();
const line = d3.line().curve(cumulative ? d3.curveMonotoneY : d3.curveLinear);
const seriesGroups = svg
.selectAll('g')
.data(series)
.join('g');
const lines = seriesGroups
.append('path')
.attr('d', d => {
let points = d[1].map(d => [
x(d[1][axisX] || zero),
y(d[1][axisY] || zero)
]);
return line(points);
})
.style('fill', 'none')
.style('stroke-width', 1.5)
.style('stroke', d => color(groupBy === 'total' ? 1 : d[1][0][1][groupBy]));
const circles = seriesGroups
.style('fill', d => color(groupBy === 'total' ? 1 : d[1][0][1][groupBy]))
.selectAll('circle')
.data(d => (showPoints ? d[1] : []))
.join('circle');
circles
.attr('r', 2.5)
.attr('cx', d => x(d[1][axisX]))
.attr('cy', d => y(d[1][axisY]));
const axis = svg.append('g');
const axisB = d3.axisBottom(x),
axisL = d3.axisLeft(y);
const formatN = d3.format(","),
logTickFormat = d => ((Math.log10(d) - Math.floor(Math.log10(d))) === 0 ? formatN(d) : "");
if (logScale) {
axisL.tickFormat(logTickFormat);
if (axisX !== "date") axisB.tickFormat(logTickFormat);
}
axis
.append('g')
.call(axisB)
.attr('transform', `translate(0, ${y(zeroAxis)})`)
.append('text')
.text(axisX === "date" ? axisX : `${cumulative ? 'cumulative' : 'daily'} ${axisX}`)
.attr('fill', `currentColor`)
.attr('text-anchor', 'end')
.attr('transform', `translate(${x.range()[1]}, ${-2})`);
axis
.append("g")
.call(axisL)
.attr('transform', `translate(${x.range()[0]}, 0)`)
.append("text")
.text(`${cumulative ? 'cumulative' : 'daily'} ${axisY}`)
.attr("fill", `currentColor`)
.attr("text-anchor", `start`)
.attr("transform", `translate(${2}, ${y.range()[1]})`);
const tooltip = svg.append('g');
const xy = [];
circles.each(function() {
xy.push([+this.getAttribute("cx"), +this.getAttribute("cy") + 2]);
});
const delaunay = d3.Delaunay.from(xy);
const numformat = d3.format(',d');
svg.on('touchmove mousemove', function() {
const m = d3.mouse(this),
i = delaunay.find(...m),
dist = Math.hypot(m[0] - xy[i][0], m[1] - xy[i][1]),
d = circles.data()[i];
if (dist < 10)
tooltip.attr("transform", `translate(${xy[i]})`).call(
callout,
`${groupBy === 'total' ? 'Total' : d[1][groupBy]}
${d[0]}
cases: ${numformat(d[1].cases)}
deaths: ${numformat(d[1].deaths)}`
);
else tooltip.call(callout, null);
});
svg.on('touchend mouseleave', () => tooltip.call(callout, null));
}
callout = (g, value) => {
if (!value) return g.style("display", "none");
g
.style("display", null)
.style("pointer-events", "none")
.style("font", "10px sans-serif");
const path = g.selectAll("path")
.data([null])
.join("path")
.attr("fill", "white")
.attr("stroke", "black");
const text = g.selectAll("text")
.data([null])
.join("text")
.call(text => text
.selectAll("tspan")
.data((value + "").split(/\n/))
.join("tspan")
.attr("x", 0)
.attr("y", (d, i) => `${i * 1.1}em`)
.style("font-weight", (_, i) => i ? null : "bold")
.text(d => d));
const {x, y, width: w, height: h} = text.node().getBBox();
text.attr("transform", `translate(${-w / 2},${15 - y})`);
path.attr("d", `M${-w / 2 - 10},5H-5l5,-5l5,5H${w / 2 + 10}v${h + 20}h-${w + 20}z`);
}
x = {
let scale;
if (axisX === 'date') {
scale = d3.scaleTime().domain(d3.extent(data, d => d.date))
} else {
scale = numericScale().domain([
1,
d3.max(series, ([, s]) => d3.max(s, ([, d]) => d[axisX]))
])
}
scale.range([120, width - 100]);
return scale;
}
y = numericScale().domain([
1,
d3.max(series, ([, s]) => d3.max(s, ([, d]) => d[axisY]))
]).range([height - 90, 40])
color = (
groupBy,
d3.scaleOrdinal(
d3.schemeCategory10.concat(d3.schemeSet2).concat(d3.schemeDark2)
)
)
numericScale = d3[logScale ? 'scaleLog' : 'scaleLinear']
height = width * 0.6
series = d3.rollups(
filteredData,
v => ({
cases: d3.sum(v, d => d.cases),
deaths: d3.sum(v, d => d.deaths),
state: v[0].state,
county: v[0].county,
fips: v[0].fips,
date: v[0].date,
}),
d => groupBy === 'total' ? 'Total' : d[groupBy],
d => d.dateString,
).reverse();
filteredData = data.filter(filter);
data = d3.csv(
'https://raw.githubusercontent.com/nytimes/covid-19-data/master/us-counties.csv',
d => {
d.dateString = d.date;
d.date = parseDate(d.date);
d.cases = +d.cases;
d.deaths = +d.deaths;
return d;
},
)
parseDate = d3.timeParse("%Y-%m-%d")
d3 = require('d3@5', 'd3-array@2', 'd3-delaunay@5')
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