Using Angular expressions for D3 accessors

This is a code excerpt from the book D3 on Angular. http://leanpub.com/d3angularjs

The data was scraped from Wikipedia on 3/15/2014: https://en.wikipedia.org/wiki/List_of_The_Walking_Dead_episodes

<!DOCTYPE html>
<html>
  <head>
    <title>Walking Dead Viewership</title>
  </head>
  <style>
    body, html{
      margin: 0;
      width: 900px;
      color: white;
      background-color: black;
      font-family: helvetica;
      margin: auto;
    }
    .scatter-container{
      width: 50%;
      float: left;
      height: 400px;
    }
    .detail{
      width: 50%;
      float: left;
      height: 400px;
    }
    scatter{
      width: 100%;
      height: 100%;
      display: block;
      z-index: 0;
      overflow: hidden;
      font-size: 10px;
    }
    scatter circle{
      opacity: 0.4;
      cursor: pointer;
      stroke-width: 2;
    }
    scatter circle:hover{
      stroke: white;
    }
    scatter text{
      fill: white;
      stroke: none;
    }
    scatter .x-axis path, scatter .y-axis path{
      stroke: none;
      fill: none;
    }
    scatter .x-axis line, scatter .y-axis line{
      stroke: rgba(255, 255, 255, 0.2);
    }
  </style>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.10/angular.min.js"></script>
  <script src="https://d3js.org/d3.v3.min.js" charset="utf-8"></script>
  <body ng-app="myApp" ng-controller="MainCtrl">
    <h1>Walking Dead Viewership</h1>
    <div class="scatter-container">
      <scatter
        data="episodes"
        accessor-x="d.air_date"
        accessor-y="d.us_viewers"
        selected-point="selectedEpisode"
        color="color(d.season)">
      </scatter>
    </div>
    <div class="detail">
      <h2>Episode: {{selectedEpisode.title}}</h2>
      <h3>season: {{selectedEpisode.season}}</h3>
      <h3>us viewers: {{selectedEpisode.us_viewers | number}}</h3>
    </div>
  </body>
  <script>

var app = angular.module('myApp', []);

app.controller('MainCtrl', function($scope, $window){
  $scope.color = d3.scale.category10();
  angular.element($window).on('resize', function(){ $scope.$apply(); });
  d3.csv('./episodes.csv', function(row){
    row.season = +row.season; // number
    row.air_date = new Date(row.air_date);
    row.us_viewers = +row.us_viewers * 1e6; // us viwers in millions
    return row;
  }, function(err, episodes){
    if(err){ throw err; }
    $scope.$apply(function(){
      // remove the few episodes that haven't air yet at time of writing.
      episodes = episodes.slice(0, -3);
      $scope.episodes = episodes;
      $scope.selectedEpisode = episodes[0];
    });
  });
});

app.directive('scatter', function(){
  function link(scope, el, attr){
    el = el[0];
    var w, h;
    var svg = d3.select(el).append('svg');
    var xAxisG = svg.append('g').attr('class', 'x-axis');
    var yAxisG = svg.append('g').attr('class', 'y-axis');
    var points = svg.append('g').attr('class', 'points').selectAll('g.point');
    var x = d3.scale.linear();
    var y = d3.scale.linear();
    var yFormat = d3.format('.2s');
    var timeFormat = d3.time.format('%m-%y');
    var xFormat = function(d){ return timeFormat(new Date(d)) };
    var xAxis = d3.svg.axis().scale(x).orient('bottom').tickFormat(xFormat);
    var yAxis = d3.svg.axis().scale(y).orient('left').tickFormat(yFormat);
    var m = 50;

scope.$watch(function(){
      w = el.clientWidth;
      h = el.clientHeight;
      return w + h;
    }, resize);

function resize(){
      svg.attr({width: w, height: h});
      x.range([m, w - m]);
      y.range([h - m, m]);
      xAxis.tickSize(-h + 2 * m);
      yAxis.tickSize(-w + 2 * m);
      xAxisG.attr('transform', 'translate(' + [0, y.range()[0] + 0.5] + ')');
      yAxisG.attr('transform', 'translate(' + [x.range()[0], 0] + ')');
      update();
    }

scope.$watch('data', update);

// update the position of all the points
      points.attr('transform', function(d){
        return 'translate(' + [x(scope.accessorX({d:d})), y(scope.accessorY({d:d}))] + ')';
      });

xAxisG.call(xAxis);
      yAxisG.call(yAxis);

};
  }
  return {
    link: link,
    restrict: 'E',
    scope: { data: '=', accessorX: '&', accessorY: '&', color: '&', selectedPoint: '=' }
  };
});
  </script>
</html>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://ajax.googleapis.com/ajax/libs/angularjs/1.2.10/angular.min.js

https://d3js.org/d3.v3.min.js