Ch. 10, Fig. 3 - D3.js in Action

This is the code for Chapter 10, Figure 3 from D3.js in Action demonstrating the d3.layout.grid() layout created in this chapter as it adjusts in size with more data added.

<html>
<head>
  <title>D3 in Action Chapter 10 - Example 1</title>
  <meta charset="utf-8" />
<script src="https://d3js.org/colorbrewer.v1.min.js" type="text/JavaScript"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
</head>
<style>
  svg {
    height: 500px;
    width: 500px;
    border: 1px solid gray;
  }
</style>
<body>
  <div id="viz">
  <svg></svg>
</div>
</body>
  <footer>
    
<script>
  
  d3.json("tweets.json", function(error, data) {
      makeAGrid(data);
    })
  
  function makeAGrid(data) {
    var scale = d3.scale.linear().domain([0,5]).range([100,400]);
    var grid = d3.layout.grid()
    var griddedData = grid(data.tweets);

d3.select("svg").selectAll("circle").data(griddedData)
    .enter()
    .append("circle")
    .attr("cx", function(d) {return scale(d.x)})
    .attr("cy", function(d) {return scale(d.y)})
    .attr("r", 20)
    .style("fill", "pink")
    
    var fakeTweets = []
    for (x = 0;x<12;x++) {
      var tweet = {id: x, content: "Fake Tweet #" + x};
      fakeTweets.push(tweet);
    }
      var doubledArray = data.tweets.concat(fakeTweets);
    
      var newGriddedData = grid(doubledArray);

d3.select("svg").selectAll("circle").data(newGriddedData)    
    .enter()
    .append("circle")
    .attr("cx", 0)
    .attr("cy", 0)
    .attr("r", 20)
    .style("fill", "darkred");

d3.select("svg").selectAll("circle")
    .transition()
    .duration(1000)
    .attr("cx", function(d) {return scale(d.x)})
    .attr("cy", function(d) {return scale(d.y)})

}
  
  d3.layout.grid = function() {
  var gridSize = [10,10];
  var gridColumns;
  var gridRows;

function processGrid(data) {

var rows = Math.ceil(Math.sqrt(data.length));
      var columns = Math.ceil(Math.sqrt(data.length));

var x = 0;

for (i = 0; i < rows; i++) { 
          for (j = 0; j < columns; j++) {
            if (data[x]) {
              data[x].x = j;
              data[x].y = i;
              x++;
            }
            else {
              break;
            }
          }
        }
      
      return data;
    }
    
    processGrid.size = function(newSize) {
      	if (!arguments.length) return gridSize;

gridSize = newSize;
        return this;
    }

return processGrid;
  }
</script>
  </footer>

</html>

Modified http://d3js.org/colorbrewer.v1.min.js to a secure url

https://d3js.org/colorbrewer.v1.min.js

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js