Visualize Data with a HeatMap

index.html

<div id="chart">
    <div id="tooltip" class="tooltip">
        <span id="Date">

         </span>
        <span id="Temp">

          </span>

        <span id="Variance">

         </span>


    </div>

script.babel

$(document).ready(function() {
    $.getJSON('https://raw.githubusercontent.com/FreeCodeCamp/ProjectReferenceData/master/global-temperature.json',
        function(data) {

            const margin = {
                    top: 20,
                    right: 20,
                    bottom: 30,
                    left: 80
                },
                width = 960 - margin.left - margin.right,
                height = 500 - margin.top - margin.bottom;
            const mL = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
                mS = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'June', 'July', 'Aug', 'Sept', 'Oct', 'Nov', 'Dec'];
            const min = d3.min(data.monthlyVariance, (d) => d.year),
                max = d3.max(data.monthlyVariance, (d) => d.year);
            let sqrWidth = width / (max - min);
            let sqrHeight = height / 12;
            const minTemp = data.baseTemperature + d3.min(data.monthlyVariance, (d) => d.variance);
            const maxTemp = data.baseTemperature + d3.max(data.monthlyVariance, (d) => d.variance);
            const tempRange = maxTemp - minTemp;
            console.log(tempRange);
            let Colors = d => d3.interpolateRgb("#fab572", "#450214")((d.variance - minTemp) / tempRange);



            const minTime = d3.min(data, d => ToSeconds(d.Time)),
                maxTime = d3.max(data, d => ToSeconds(d.Time));

            let x = d3.scaleLinear().range([0, width]).domain([min, max + 1]),
                y = d3.scaleLinear().range([height, 0]).domain([0, 12]);


            let chart = d3.select("#chart").append("svg")
                .attr("class", "chart")
                .attr("width", width + margin.left + margin.right)
                .attr("height", height + margin.top + margin.bottom)
                .append("g")
                .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

            let valArr = [];
            for (let i = min + 1; i < max; i++)
                if (!(i % 10))
                    valArr.push(i);


            let xAxis = d3.axisBottom(x).tickValues(valArr).tickFormat(d3.format("d")),
                yAxis = d3.axisLeft(y).tickFormat((m) => m ? mL[m - 1] : "");


            // x-axis
            chart.append("g")
                .attr("class", "x-axis")
                .attr("transform", "translate(0," + height + ")")
                .call(xAxis);


            // y-axis
            chart.append("g")
                .attr("class", "y-axis")
                .call(yAxis);



            chart.selectAll(".tile")
                .data(data.monthlyVariance)
                .enter().append("rect")
                .attr("class", "tile")
                .attr("x", function(d) {
                    return x(d.year);
                })
                .attr("y", function(d) {
                    return y(d.month);
                })
                .attr("width", sqrWidth)
                .attr("height", sqrHeight)
                .style("fill", (d) => Colors(d))
                .on("mouseover", function() {
                    d3.select('#tooltip').style("visibility", "visible")
                })
                .on("mousemove", function(d, i) {
                    d3.select('#tooltip').style("top", (d3.event.pageY - 10) + "px").style("left", (d3.event.pageX + 10) + "px");
                    d3.select('#Date').text(d.year + " - " + mL[d.month - 1]);

                    d3.select('#Temp').text((data.baseTemperature + d.variance).toFixed(3) + " ℃");
                    d3.select('#Variance').text(d.variance);

                })
                .on("mouseout", function() {
                    d3.select('#tooltip').style("visibility", "hidden");

                });


        });
})

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.2.2/d3.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/zepto/1.2.0/zepto.min.js"></script>

style.css

body {
  background:lavender;
    width: 100%;
    height: 100;
    display:flex;
    align-items: center;
    align-content: center;
    justify-content: center;
    flex-flow: column;
    font: 11px sans-serif;
      }

        .axis path {
            fill: none;
            stroke: #000;
            shape-rendering: crispEdges;
        }

        .dot {
            stroke: #000;
        }

        .tooltip {
            position: absolute;
            width: auto;
            height: auto;
            pointer-events: none;
            color: black;
            padding: 6px;
            background-color: rgba(70, 130, 180,0.65);
            font-family: sans-serif;
            font-size: 70%;
            visibility: hidden;
            z-index: 10;
            display: flex;
            flex-flow: column;
            align-items: center;
            align-content: center;
            text-align: center;
            border-radius: 10px
             /*opacity: 0.65;*/
        }
        .tooltip > span{
            margin-top: 3%;
        }

visualize-data-with-a-heatmap.markdown

Visualize Data with a HeatMap

A Pen by christos on CodePen.

License.