Merge branch 'master' of git://github.com/snoble/d3 into 2.10.0

d3.v2.js

@@ -2922,7 +2922,7 @@
   function d3_svg_lineFiniteDifferences(points) {
     var i = 0, j = points.length - 1, m = [], p0 = points[0], p1 = points[1], d = m[0] = d3_svg_lineSlope(p0, p1);
     while (++i < j) {
-      m[i] = d + (d = d3_svg_lineSlope(p0 = p1, p1 = points[i + 1]));
+      m[i] = (d + (d = d3_svg_lineSlope(p0 = p1, p1 = points[i + 1]))) / 2;
     }
     m[i] = d;
     return m;

src/svg/line.js

@@ -358,7 +358,7 @@ function d3_svg_lineFiniteDifferences(points) {
       p1 = points[1],
       d = m[0] = d3_svg_lineSlope(p0, p1);
   while (++i < j) {
-    m[i] = d + (d = d3_svg_lineSlope(p0 = p1, p1 = points[i + 1]));
+    m[i] = (d + (d = d3_svg_lineSlope(p0 = p1, p1 = points[i + 1]))) / 2;
   }
   m[i] = d;
   return m;