熱力圖效果圖如下油额，支持縮放

<div id="data_div" style="background-color: rgb(190, 228, 155); width:'500px'; height: '500px'; ">

</div>

setChart() {

? ? const margin = {top: 80, right: 25, bottom: 30, left: 40},

? ? width = 450 - margin.left - margin.right,

? ? height = 450 - margin.top - margin.bottom;

? ? // append the svg object to the body of the page

? ? const svg = d3.select("#data_div")

? ? ? .append("svg")

? ? ? ? .attr("width", width + margin.left + margin.right)

? ? ? ? .attr("height", height + margin.top + margin.bottom)

? ? ? ? .call(d3.zoom().on("zoom", function (event) { ?// 控制縮放

? ? ? ? ? svg.attr("transform", event.transform)

? ? ? ? }))

? ? ? .append("g")

? ? ? ? .attr("transform", `translate(${margin.left}, ${margin.top})`);

? ? //Read the data

? ? const data = [

? ? ? {group:'A', variable:'V1', value:'30'},

? ? ? {group:'A', variable:'V2', value:'60'},

? ? ? {group:'A', variable:'V4', value:'40'},

? ? ? {group:'B', variable:'V1', value:'50'},

? ? ? {group:'B', variable:'V2', value:'80'},

? ? ? {group:'C', variable:'V3', value:'70'},

? ? ? {group:'C', variable:'V1', value:'40'},

? ? ? {group:'D', variable:'V3', value:'90'},

? ? ? {group:'D', variable:'V4', value:'80'},

? ? ? {group:'E', variable:'V4', value:'50'},

? ? ? {group:'E', variable:'V5', value:'80'},

? ? ? {group:'F', variable:'V5', value:'60'},

? ? ? {group:'F', variable:'V6', value:'70'},

? ? ];

? ? // Labels of row and columns -> unique identifier of the column called 'group' and 'variable'

? ? const myGroups = Array.from(new Set(data.map(d => d.group)))

? ? const myVars = Array.from(new Set(data.map(d => d.variable)))

? ? // Build X scales and axis,Y scales and axis:

? ? const x = d3.scaleBand()

? ? ? .range([ 0, width ])

? ? ? .domain(myGroups)

? ? ? .padding(0.05);

? ? svg.append("g")

? ? ? .style("font-size", 15)

? ? ? .attr("transform", `translate(0, ${height})`)

? ? ? .call(d3.axisBottom(x).tickSize(0))???// tickSize(0) 去掉坐標(biāo)點(diǎn)的指示線

? ? ? .select(".domain").remove()??// 去掉X軸的坐標(biāo)線

? ? const y = d3.scaleBand()

? ? ? .range([ height, 0 ])

? ? ? .domain(myVars)

? ? ? .padding(0.05);

? ? svg.append("g")

? ? ? .style("font-size", 15)

? ? ? .call(d3.axisLeft(y).tickSize(0))

? ? ? .select(".domain").remove()

? ? // Build color scale

? ? const myColor = d3.scaleSequential()

? ? ? .interpolator(d3.interpolateInferno)

? ? ? .domain([1,100])

? ? // create a tooltip

? ? const tooltip = d3.select("#data_div")

? ? ? .append("div")

? ? ? .style("opacity", 0)

? ? ? .attr("class", "tooltip")

? ? ? .style("background-color", "cyan")

? ? ? .style("border", "solid")

? ? ? .style("border-width", "1px")

? ? ? .style("border-radius", "5px")

? ? ? .style("padding", "5px")

? ? // Three function that change the tooltip when user hover / move / leave a cell

? ? const mouseover = function(event,d) {

? ? ? tooltip

? ? ? ? .style("opacity", 1)

? ? ? d3.select(this)

? ? ? ? .style("stroke", "black")

? ? ? ? .style("opacity", 1)

? ? }

? ? const mousemove = function(event,d) {

? ? ? tooltip

? ? ? ? .html("The exact value of<br>this cell is: " + d.value)

? ? ? ? .style("left", "120px")

? ? ? ? .style("top", ((event.x)/2 + 11) + "px")

? ? }

? ? const mouseleave = function(event,d) {

? ? ? tooltip

? ? ? ? .style("opacity", 0)

? ? ? d3.select(this)

? ? ? ? .style("stroke", "none")

? ? ? ? .style("opacity", 0.8)

? ? }

? ? // add the squares

? ? svg.selectAll()

? ? ? .data(data, function(d) {return d.group+':'+d.variable;})

? ? ? .join("rect")

? ? ? ? .attr("x", function(d) { return x(d.group) })

? ? ? ? .attr("y", function(d) { return y(d.variable) })

? ? ? ? .attr("rx", 4)

? ? ? ? .attr("ry", 4)

? ? ? ? .attr("width", x.bandwidth() )

? ? ? ? .attr("height", y.bandwidth() )

? ? ? ? .style("fill", function(d) { return myColor(d.value)} )

? ? ? ? .style("stroke-width", 4)

? ? ? ? .style("stroke", "none")

? ? ? ? .style("opacity", 0.8)

? ? ? .on("mouseover", mouseover)

? ? ? .on("mousemove", mousemove)

? ? ? .on("mouseleave", mouseleave)

? ? // Add title to graph

? ? svg.append("text")

? ? ? .attr("x", 0)

? ? ? .attr("y", -50)

? ? ? .attr("text-anchor", "left")

? ? ? .style("font-size", "22px")

? ? ? .text("A d3.js heatmap");

? ? // Add subtitle to graph

? ? svg.append("text")

? ? ? .attr("x", 0)

? ? ? .attr("y", -20)

? ? ? .attr("text-anchor", "left")

? ? ? .style("font-size", "14px")

? ? ? .style("fill", "grey")

? ? ? .style("max-width", 400)

? ? ? .text("A short description of the take-away message of this chart.");

? }