--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/layout/pie.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,95 @@
+d3.layout.pie = function() {
+  var value = Number,
+      sort = d3_layout_pieSortByValue,
+      startAngle = 0,
+      endAngle = 2 * Math.PI;
+
+  function pie(data, i) {
+
+    // Compute the numeric values for each data element.
+    var values = data.map(function(d, i) { return +value.call(pie, d, i); });
+
+    // Compute the start angle.
+    var a = +(typeof startAngle === "function"
+        ? startAngle.apply(this, arguments)
+        : startAngle);
+
+    // Compute the angular scale factor: from value to radians.
+    var k = ((typeof endAngle === "function"
+        ? endAngle.apply(this, arguments)
+        : endAngle) - startAngle)
+        / d3.sum(values);
+
+    // Optionally sort the data.
+    var index = d3.range(data.length);
+    if (sort != null) index.sort(sort === d3_layout_pieSortByValue
+        ? function(i, j) { return values[j] - values[i]; }
+        : function(i, j) { return sort(data[i], data[j]); });
+
+    // Compute the arcs!
+    var arcs = index.map(function(i) {
+      return {
+        data: data[i],
+        value: d = values[i],
+        startAngle: a,
+        endAngle: a += d * k
+      };
+    });
+
+    // Return the arcs in the original data's order.
+    return data.map(function(d, i) {
+      return arcs[index[i]];
+    });
+  }
+
+  /**
+   * Specifies the value function *x*, which returns a nonnegative numeric value
+   * for each datum. The default value function is `Number`. The value function
+   * is passed two arguments: the current datum and the current index.
+   */
+  pie.value = function(x) {
+    if (!arguments.length) return value;
+    value = x;
+    return pie;
+  };
+
+  /**
+   * Specifies a sort comparison operator *x*. The comparator is passed two data
+   * elements from the data array, a and b; it returns a negative value if a is
+   * less than b, a positive value if a is greater than b, and zero if a equals
+   * b.
+   */
+  pie.sort = function(x) {
+    if (!arguments.length) return sort;
+    sort = x;
+    return pie;
+  };
+
+  /**
+   * Specifies the overall start angle of the pie chart. Defaults to 0. The
+   * start angle can be specified either as a constant or as a function; in the
+   * case of a function, it is evaluated once per array (as opposed to per
+   * element).
+   */
+  pie.startAngle = function(x) {
+    if (!arguments.length) return startAngle;
+    startAngle = x;
+    return pie;
+  };
+
+  /**
+   * Specifies the overall end angle of the pie chart. Defaults to 2π. The
+   * end angle can be specified either as a constant or as a function; in the
+   * case of a function, it is evaluated once per array (as opposed to per
+   * element).
+   */
+  pie.endAngle = function(x) {
+    if (!arguments.length) return endAngle;
+    endAngle = x;
+    return pie;
+  };
+
+  return pie;
+};
+
+var d3_layout_pieSortByValue = {};