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Bubble Maps in JavaScript

How to make a D3.js-based bubble map in JavaScript. A bubble map overlays a bubble chart on a map.


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Plotly is a free and open-source graphing library for JavaScript. We recommend you read our Getting Started guide for the latest installation or upgrade instructions, then move on to our Plotly Fundamentals tutorials or dive straight in to some Basic Charts tutorials.

var data = [{
    type: 'scattergeo',
    mode: 'markers',
    locations: ['FRA', 'DEU', 'RUS', 'ESP'],
    marker: {
        size: [20, 30, 15, 10],
        color: [10, 20, 40, 50],
        cmin: 0,
        cmax: 50,
        colorscale: 'Greens',
        colorbar: {
            title: 'Some rate',
            ticksuffix: '%',
            showticksuffix: 'last'
        },
        line: {
            color: 'black'
        }
    },
    name: 'europe data'
}];

var layout = {
    'geo': {
        'scope': 'europe',
        'resolution': 50
    }
};

Plotly.newPlot('myDiv', data, layout);
Plotly.d3.csv('https://raw.githubusercontent.com/plotly/datasets/master/2014_us_cities.csv', function(err, rows){

    function unpack(rows, key) {
        return rows.map(function(row) { return row[key]; });
    }

    var cityName = unpack(rows, 'name'),
        cityPop = unpack(rows, 'pop'),
        cityLat = unpack(rows, 'lat'),
        cityLon = unpack(rows, 'lon'),
        color = [,"rgb(255,65,54)","rgb(133,20,75)","rgb(255,133,27)","lightgrey"],
        citySize = [],
        hoverText = [],
        scale = 50000;

    for ( var i = 0 ; i < cityPop.length; i++) {
        var currentSize = cityPop[i] / scale;
        var currentText = cityName[i] + " pop: " + cityPop[i];
        citySize.push(currentSize);
        hoverText.push(currentText);
    }

    var data = [{
        type: 'scattergeo',
        locationmode: 'USA-states',
        lat: cityLat,
        lon: cityLon,
        hoverinfo: 'text',
        text: hoverText,
        marker: {
            size: citySize,
            line: {
                color: 'black',
                width: 2
            },
        }
    }];

    var layout = {
        title: '2014 US City Populations',
        showlegend: false,
        geo: {
            scope: 'usa',
            projection: {
                type: 'albers usa'
            },
            showland: true,
            landcolor: 'rgb(217, 217, 217)',
            subunitwidth: 1,
            countrywidth: 1,
            subunitcolor: 'rgb(255,255,255)',
            countrycolor: 'rgb(255,255,255)'
        },
    };

    Plotly.newPlot("myDiv", data, layout, {showLink: false});

});