interactive-vis-course/Week11/us_states_data_leaflet.html at gh-pages · arnicas/interactive-vis-course · GitHub

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<!DOCTYPE html>
<! A mod of Michelle Chandra's block: http://bl.ocks.org/michellechandra/0b2ce4923dc9b5809922 -->
<html lang="en">
<head>
<meta charset="utf-8">
<style type="text/css">

@import url(//cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.5/leaflet.css);

/* On mouse hover, lighten state color */
path {
    stroke: gray;
    stroke-width: 1;
    fill-opacity: .7;
}

circle {
    fill: orange;
    fill-opacity: .8;
}

p.intro {
    width: 500px;
}

/* Style for Custom Tooltip */
div.tooltip {
    position: absolute;
    text-align: center;
    min-width: 100px;
    height: 30px;
    padding: 2px;
    font: 12px sans-serif;
    background: white;
    border: 1px orange solid;
    border-radius: 5px;
    pointer-events: none;
}

.tooltip p {
    margin: 5px;
}

/* Legend Font Style */
body {
    font: 11px sans-serif;
}

#map {
  width: 960px;
  height: 500px;

/* Legend Position Style */
.legend {
    position:absolute;
    left:800px;
    top:350px;
}

</style>
</head>
<body>

    <h2>A Leaflet Map Showing States Michelle Visited and Cities She Lived In</h2>

    <p class="intro">A modified version of the <a href="http://bl.ocks.org/michellechandra/0b2ce4923dc9b5809922">block by Michelle Chandra</a> (data mod'd too).
        This example shows joining data to a geojson file from external files, using queue and d3.legend. Also plots on top of Leaflet, based on <a href="https://bost.ocks.org/mike/leaflet/">example from Mike B.</a></p>

    <div id="map"></div>

<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="https://d3js.org/queue.v1.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.5/leaflet.js"></script>
<script>

var map = new L.Map("map", {center: [37.8, -96.9], zoom: 4})
    .addLayer(new L.TileLayer("http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"));

var svg = d3.select(map.getPanes().overlayPane).append("svg"),
    g = svg.append("g").attr("class", "leaflet-zoom-hide");

// Define linear scale for output
var stateColor = d3.scale.linear()
              .range(["white", "pink"]);


// Append Div for tooltip to SVG
var div = d3.select("body")
            .append("div")
            .attr("class", "tooltip")
            .style("display", "none");

queue()
    .defer(d3.json, "data/geojson/us-states.json")
    .defer(d3.csv, "data/states-visited.csv")
    .defer(d3.csv, "data/cities-lived.csv")
    .await(ready);


function ready(error, json, states, cities) {

    var transform = d3.geo.transform({point: projectPoint});
    var path = d3.geo.path().projection(transform);

    stateColor.domain(d3.extent(states,function(s) { return s.visits;})); // setting the range of the input data

    // Loop through each state data value in the .csv file
    states.forEach(function(state) {
        // Grab State Name
        var dataState = state.statename; // name
        // Grab data value
        var dataValue = +state.visits; // number

        // Find the corresponding state inside the GeoJSON
        json.features.forEach(function(j) {
            var jsonState = j.properties.name;
            if (dataState == jsonState) { // assumes the names will match...
                // Copy the data value into the JSON
                j.properties.visited = dataValue;
            // Stop looking through the JSON
            }
        });
    }); // ends data merge


    // Bind the data to the SVG and create one path per GeoJSON feature
    var feature = g.selectAll("path")
        .data(json.features)
        .enter()
        .append("path")
        .attr("d", path)
        .style("fill", function(d) {
            // Get data value for visited
            var value = d.properties.visited;
            return stateColor(value);
        });


    var circles = g.selectAll("circle")
        .data(cities)
        .enter()
        .append("circle")
        .attr("cx", function(d) {
            return getPoint(d.lon, d.lat).x;
        })
        .attr("cy", function(d) {
            return getPoint(d.lon, +d.lat).y;
        })
        .attr("r", function(d) {
            return Math.sqrt(d.years) * 4;
        })
        .on("mouseover", function(d) {
            div.transition()
               .duration(200)
               .style("display", null);
            div.html("<p>Lived in " + d.name + " for " + d.years + " year(s).</p>")
               .style("left", (d3.event.pageX + 10) + "px")
               .style("top", (d3.event.pageY - 28) + "px");
        })
        // fade out tooltip on mouse out
        .on("mouseout", function(d) {
            div.transition()
               .duration(500)
               .style("display", "none");
        });

    map.on("viewreset", reset);
    reset();

  // Reposition the SVG to cover the features.
  function reset() {
    var bounds = path.bounds(json),
        topLeft = bounds[0],
        bottomRight = bounds[1];

    svg.attr("width", bottomRight[0] - topLeft[0])
        .attr("height", bottomRight[1] - topLeft[1])
        .style("left", topLeft[0] + "px")
        .style("top", topLeft[1] + "px");

    g.attr("transform", "translate(" + -topLeft[0] + "," + -topLeft[1] + ")");

    feature.attr("d", path);
    circles.transition()
        .attr("cx", function(d) {
            return getPoint(d.lon, d.lat).x;
        })
        .attr("cy", function(d) {
            return getPoint(d.lon, +d.lat).y;
        });
  }

  function getPoint(x, y) {
    // d3 uses lon, lat, leafleft uses lat,lon.
    //console.log(map.latLngToLayerPoint(new L.LatLng(y,x)));
    // this returns an object with .x and .y attributes
    return map.latLngToLayerPoint(new L.LatLng(y,x));
  }

  // Use Leaflet to implement a D3 geometric transformation.
  function projectPoint(x, y) {
    var point = map.latLngToLayerPoint(new L.LatLng(y, x));
    this.stream.point(point.x, point.y);
  }


} // end ready function

</script>
</body>
</html>