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Add names of the states to a map in d3.js

I am using albersUSA projection to display a map. I want to add the name of the states to each state.

This is what I tried, and i can see the names of the states in the source, but I don't see them rendered. What am i doing wrong?

var width = 1060,
height = 600,

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

svg.append("rect")
    .attr("class", "background")
    .attr("width", width)
    .attr("height", height)
    .on("click", click)
    .on("mousemove", mousemove);

var g = svg.append("g")
    .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")")
    .append("g")
    .attr("id", "states");

var projection = d3.geo.albersUsa()
    .scale(width)
    .translate([0, 100]);

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

draw();

function draw(){

  d3.json("readme.json", function(json) {
    g.selectAll("path")
    .data(json.features)
    .enter()
    .append("path")
    .attr("d", path)
    .append("svg:text")
    .text(function(d){
        return d.properties.name;
    })
    .attr("x", function(d){
        return -path.centroid(d)[0];
    })
    .attr("y", function(d){
        return  -path.centroid(d)[1];
    });

  });
}
like image 718
ashwnacharya Avatar asked Dec 16 '12 00:12

ashwnacharya


2 Answers

OK for anyone wondering, this is how I managed to do it:

function draw(){

  d3.json("readme.json", function(json) {
    g.selectAll("path")
    .data(json.features)
    .enter()
    .append("path")
    .attr("d", path)
    .on("click", click);

    g.selectAll("text")
    .data(json.features)
    .enter()
    .append("svg:text")
    .text(function(d){
        return d.properties.name;
    })
    .attr("x", function(d){
        return path.centroid(d)[0];
    })
    .attr("y", function(d){
        return  path.centroid(d)[1];
    })
    .attr("text-anchor","middle")
    .attr('font-size','6pt');


  });
}
like image 196
ashwnacharya Avatar answered Nov 08 '22 01:11

ashwnacharya


I took a similar approach to the answer you provided yourself, but I didn't like where "centroid" put all of the state names. Hawaii, Louisiana, Michigan, and Florida, for instance. So I added properties to the json data for the state info for dx and dy for those states, and added code to the drawing function.

Here's an example of some of the modified states (with the coordinates removed to keep it smaller):

    {
        "geometry": { "type": "Polygon", "coordinates": [] },
        "type": "Feature",
        "id": "12",
        "properties": { "name": "Florida", "abbr": "FL", "dx": "1em" }
    },
    {
        "geometry": { "type": "MultiPolygon", "coordinates": [] },
        "type": "Feature",
        "id": "15",
        "properties": { "name": "Hawaii", "abbr": "HI", "dx": "1.15em", "dy": "1.25em" }
    },

And here is the portion of the function that draws the labels:

        g.selectAll("text")
            .data(json.features)
            .enter()
            .append("text")
            .attr("transform", function (d) { return "translate(" + path.centroid(d) + ")"; })
            .attr("dx", function (d) { return d.properties.dx || "0"; })
            .attr("dy", function (d) { return d.properties.dy || "0.35em"; })
            .text(function (d) { return d.properties.abbr; });
like image 39
jfren484 Avatar answered Nov 08 '22 00:11

jfren484