Modify target aspect ratio implementation.

d3.layout.js

@@ -1496,12 +1496,14 @@ function d3_layout_treeAncestor(vim, node, ancestor) {
       : ancestor;
 }
 // Squarified Treemaps by Mark Bruls, Kees Huizing, and Jarke J. van Wijk
+// Modified to support a target aspect ratio by Jeff Heer
 d3.layout.treemap = function() {
   var hierarchy = d3.layout.hierarchy(),
       round = Math.round,
       size = [1, 1], // width, height
       sticky = false,
-      stickies;
+      stickies,
+      ratio = 0.5 * (1 + Math.sqrt(5)); // golden ratio
 
   // Recursively compute the node area based on value & scale.
   function scale(node, k) {
@@ -1582,7 +1584,7 @@ d3.layout.treemap = function() {
     }
     s *= s;
     u *= u;
-    return Math.max((u * rmax) / s, s / (u * rmin));
+    return Math.max((u * rmax * ratio) / s, s / (u * rmin * ratio));
   }
 
   // Positions the specified row of nodes. Modifies `rect`.
@@ -1659,6 +1661,12 @@ d3.layout.treemap = function() {
     return treemap;
   };
 
+  treemap.ratio = function(x) {
+    if (!arguments.length) return ratio;
+    ratio = x;
+    return treemap;
+  };
+
   return treemap;
 };
 })()

examples/treemap/treemap.js

@@ -6,7 +6,8 @@ var treemap = d3.layout.treemap()
     .size([w, h])
     .children(function(d) { return isNaN(d.value) ? d3.entries(d.value) : null; })
     .value(function(d) { return d.value; })
-    .sticky(true);
+    .sticky(true)
+    .ratio(+location.search.substring(1));
 
 var div = d3.select("#chart").append("div")
     .style("position", "relative")

src/layout/treemap.js

@@ -6,7 +6,7 @@ d3.layout.treemap = function() {
       size = [1, 1], // width, height
       sticky = false,
       stickies,
-      target = 0.5 * (1 + Math.sqrt(5));
+      ratio = 0.5 * (1 + Math.sqrt(5)); // golden ratio
 
   // Recursively compute the node area based on value & scale.
   function scale(node, k) {
@@ -87,9 +87,7 @@ d3.layout.treemap = function() {
     }
     s *= s;
     u *= u;
-	r = Math.abs((u * rmax) / s - target);
+    return Math.max((u * rmax * ratio) / s, s / (u * rmin * ratio));
-	s = Math.abs(s / (u * rmin) - target);
-    return Math.max(r, s);
   }
 
   // Positions the specified row of nodes. Modifies `rect`.
@@ -166,9 +164,9 @@ d3.layout.treemap = function() {
     return treemap;
   };
 
-  treemap.target = function(x) {
+  treemap.ratio = function(x) {
-    if (!arguments.length) return target;
+    if (!arguments.length) return ratio;
-    target = x;
+    ratio = x;
     return treemap;
   };