1 // Ratio of Obese (BMI >= 30) in U.S. Adults, CDC 2008

     2 var data = [

     3   , .187, .198, , .133, .175, .151, , .1, .125, .171, , .172, .133, , .108,

     4   .142, .167, .201, .175, .159, .169, .177, .141, .163, .117, .182, .153, .195,

     5   .189, .134, .163, .133, .151, .145, .13, .139, .169, .164, .175, .135, .152,

     6   .169, , .132, .167, .139, .184, .159, .14, .146, .157, , .139, .183, .16, .143

     7 ];

     8 

     9 var svg = d3.select("#chart").append("svg:svg")

    10     .attr("width", 960)

    11     .attr("height", 500);

    12 

    13 d3.json("../data/us-states.json", function(json) {

    14   var path = d3.geo.path();

    15 

    16   // A thick black stroke for the exterior.

    17   svg.append("svg:g")

    18       .attr("class", "black")

    19     .selectAll("path")

    20       .data(json.features)

    21     .enter().append("svg:path")

    22       .attr("d", path);

    23 

    24   // A white overlay to hide interior black strokes.

    25   svg.append("svg:g")

    26       .attr("class", "white")

    27     .selectAll("path")

    28       .data(json.features)

    29     .enter().append("svg:path")

    30       .attr("d", path);

    31 

    32   // The polygons, scaled!

    33   svg.append("svg:g")

    34       .attr("class", "grey")

    35     .selectAll("path")

    36       .data(json.features)

    37     .enter().append("svg:path")

    38       .attr("d", path)

    39       .attr("transform", function(d) {

    40         var centroid = path.centroid(d),

    41             x = centroid[0],

    42             y = centroid[1];

    43         return "translate(" + x + "," + y + ")"

    44             + "scale(" + Math.sqrt(data[+d.id] * 5 || 0) + ")"

    45             + "translate(" + -x + "," + -y + ")";

    46       })

    47       .style("stroke-width", function(d) {

    48         return 1 / Math.sqrt(data[+d.id] * 5 || 1);

    49       });

    50 

    51 });