Fix big with constant greatArc target.

The local variable `t` was masking the private field of the same name. The use
of single-letter variables is preferred for smaller scopes.

Author: mbostock

d3.js

@@ -6159,9 +6159,9 @@
     return interpolate;
   }
   d3.geo.greatArc = function() {
-    var source = d3_source, s, target = d3_target, t, precision = 6 * d3_radians, interpolate;
+    var source = d3_source, source_, target = d3_target, target_, precision = 6 * d3_radians, interpolate;
     function greatArc() {
-      var p0 = s || source.apply(this, arguments), p1 = t || target.apply(this, arguments), i = interpolate || d3.geo.interpolate(p0, p1), t = 0, dt = precision / i.distance, coordinates = [ p0 ];
+      var p0 = source_ || source.apply(this, arguments), p1 = target_ || target.apply(this, arguments), i = interpolate || d3.geo.interpolate(p0, p1), t = 0, dt = precision / i.distance, coordinates = [ p0 ];
       while ((t += dt) < 1) coordinates.push(i(t));
       coordinates.push(p1);
       return {
@@ -6170,18 +6170,18 @@
       };
     }
     greatArc.distance = function() {
-      return (interpolate || d3.geo.interpolate(s || source.apply(this, arguments), t || target.apply(this, arguments))).distance;
+      return (interpolate || d3.geo.interpolate(source_ || source.apply(this, arguments), target_ || target.apply(this, arguments))).distance;
     };
     greatArc.source = function(_) {
       if (!arguments.length) return source;
-      source = _, s = typeof _ === "function" ? null : _;
-      interpolate = s && t ? d3.geo.interpolate(s, t) : null;
+      source = _, source_ = typeof _ === "function" ? null : _;
+      interpolate = source_ && target_ ? d3.geo.interpolate(source_, target_) : null;
       return greatArc;
     };
     greatArc.target = function(_) {
       if (!arguments.length) return target;
-      target = _, t = typeof _ === "function" ? null : _;
-      interpolate = s && t ? d3.geo.interpolate(s, t) : null;
+      target = _, target_ = typeof _ === "function" ? null : _;
+      interpolate = source_ && target_ ? d3.geo.interpolate(source_, target_) : null;
       return greatArc;
     };
     greatArc.precision = function(_) {

d3.min.js

@@ -1,12 +1,12 @@
 d3.geo.greatArc = function() {
-  var source = d3_source, s,
-      target = d3_target, t,
+  var source = d3_source, source_,
+      target = d3_target, target_,
       precision = 6 * d3_radians,
       interpolate;
 
   function greatArc() {
-    var p0 = s || source.apply(this, arguments),
-        p1 = t || target.apply(this, arguments),
+    var p0 = source_ || source.apply(this, arguments),
+        p1 = target_ || target.apply(this, arguments),
         i = interpolate || d3.geo.interpolate(p0, p1),
         t = 0,
         dt = precision / i.distance,
@@ -18,20 +18,20 @@ d3.geo.greatArc = function() {
 
   // Length returned in radians; multiply by radius for distance.
   greatArc.distance = function() {
-    return (interpolate || d3.geo.interpolate(s || source.apply(this, arguments), t || target.apply(this, arguments))).distance;
+    return (interpolate || d3.geo.interpolate(source_ || source.apply(this, arguments), target_ || target.apply(this, arguments))).distance;
   };
 
   greatArc.source = function(_) {
     if (!arguments.length) return source;
-    source = _, s = typeof _ === "function" ? null : _;
-    interpolate = s && t ? d3.geo.interpolate(s, t) : null;
+    source = _, source_ = typeof _ === "function" ? null : _;
+    interpolate = source_ && target_ ? d3.geo.interpolate(source_, target_) : null;
     return greatArc;
   };
 
   greatArc.target = function(_) {
     if (!arguments.length) return target;
-    target = _, t = typeof _ === "function" ? null : _;
-    interpolate = s && t ? d3.geo.interpolate(s, t) : null;
+    target = _, target_ = typeof _ === "function" ? null : _;
+    interpolate = source_ && target_ ? d3.geo.interpolate(source_, target_) : null;
     return greatArc;
   };
 

src/geo/greatArc.js

@@ -17,6 +17,26 @@ suite.addBatch({
         target: [ 73 + 47 / 60, 40 + 38 / 60]
       }), 3973 / 6371, .5);
     },
+    "source and target can be set as constants": function() {
+      var arc = d3.geo.greatArc()
+          .source([5, 52])
+          .target([-120, 37])
+          .precision(7.2);
+      assert.inDelta(arc().coordinates, [
+        [   5,        52      ],
+        [  -3.805036, 57.05083],
+        [ -15.122869, 61.30118],
+        [ -29.396213, 64.34584],
+        [ -46.132729, 65.72409],
+        [ -63.394401, 65.15597],
+        [ -78.854311, 62.76337],
+        [ -91.401599, 58.96701],
+        [-101.190927, 54.21333],
+        [-108.843633, 48.83586],
+        [-114.961152, 43.05231],
+        [-120,        37      ]
+      ], .5);
+    },
     "geodesic": function(arc) {
       assert.inDelta(arc.precision(7.2)({source: [5, 52], target: [-120, 37]}).coordinates, [
         [   5,        52      ],