diff --git a/examples/mapping/app.js b/examples/mapping/app.js
index f787508..94ce4b4 100644
--- a/examples/mapping/app.js
+++ b/examples/mapping/app.js
@@ -1,19 +1,21 @@
var width = 960;
var height = 490;
+//set the height/width of the svg
d3.select('svg')
.attr('width', width)
.attr('height', height);
+//choose a project that works with our data
var worldProjection = d3.geoEquirectangular();
-d3.select('svg').selectAll('path')
- .data(map_json.features)
- .enter()
- .append('path')
- .attr('fill', '#099');
+d3.select('svg').selectAll('path') //select all path elements within the svg, even if none exist
+ .data(map_json.features) //link the features array of our data to that selection
+ .enter() //find the data elements not associated with paths
+ .append('path') //append a path for each unmatch data element
+ .attr('fill', '#099'); //set the fill for all paths
-var dAttributeFunction = d3.geoPath()
+var dAttributeFunction = d3.geoPath() //create a path drawing function that will use our worldProjection
.projection(worldProjection);
-d3.selectAll('path').attr('d', dAttributeFunction);
+d3.selectAll('path').attr('d', dAttributeFunction); //use that function to modify the d attribute of all path elements
diff --git a/examples/mapping/index.html b/examples/mapping/index.html
index 1d256ad..393720f 100644
--- a/examples/mapping/index.html
+++ b/examples/mapping/index.html
@@ -4,6 +4,7 @@
+