JavaScriptCollection
diff --git a/‎d3.js‎
Lines changed: 7 additions & 3 deletions b/‎d3.js‎
Lines changed: 7 additions & 3 deletions
diff --git a/‎d3.min.js‎
Lines changed: 2 additions & 2 deletions b/‎d3.min.js‎
Lines changed: 2 additions & 2 deletions
diff --git a/‎src/arrays/median.js‎
Lines changed: 12 additions & 3 deletions b/‎src/arrays/median.js‎
Lines changed: 12 additions & 3 deletions
diff --git a/‎test/arrays/median-test.js‎
Lines changed: 8 additions & 0 deletions b/‎test/arrays/median-test.js‎
Lines changed: 8 additions & 0 deletions
@@ -104,9 +104,13 @@
     return e ? v + e * (values[h] - v) : v;
   };
   d3.median = function(array, f) {
-    if (arguments.length > 1) array = array.map(f);
-    array = array.filter(d3_number);
-    return array.length ? d3.quantile(array.sort(d3_ascending), .5) : undefined;
+    var array1 = [], n = array.length, a, i = -1;
+    if (arguments.length === 1) {
+      while (++i < n) if (d3_number(a = array[i])) array1.push(+a);
+    } else {
+      while (++i < n) if (d3_number(a = f.call(array, array[i], i))) array1.push(+a);
+    }
+    return array1.length ? d3.quantile(array1.sort(d3_ascending), .5) : undefined;
   };
   function d3_bisector(compare) {
     return {
 
@@ -3,7 +3,16 @@ import "ascending";
 import "quantile";
 
 d3.median = function(array, f) {
-  if (arguments.length > 1) array = array.map(f);
-  array = array.filter(d3_number);
-  return array.length ? d3.quantile(array.sort(d3_ascending), .5) : undefined;
+  var array1 = [],
+      n = array.length,
+      a,
+      i = -1;
+
+  if (arguments.length === 1) {
+    while (++i < n) if (d3_number(a = array[i])) array1.push(+a);
+  } else {
+    while (++i < n) if (d3_number(a = f.call(array, array[i], i))) array1.push(+a);
+  }
+
+  return array1.length ? d3.quantile(array1.sort(d3_ascending), .5) : undefined;
 };
@@ -32,6 +32,14 @@ suite.addBatch({
     "applies the optional accessor function": function(median) {
       assert.equal(median([[1, 2, 3, 4, 5], [2, 4, 6, 8, 10]], function(d) { return median(d); }), 4.5);
       assert.equal(median([1, 2, 3, 4, 5], function(d, i) { return i; }), 2);
+    },
+    "coerces strings to numbers": function(median) {
+      assert.equal(median(["1"]), 1);
+      assert.equal(median(["5", "1", "2", "3", "4"]), 3);
+      assert.equal(median(["20", "3"]), 11.5);
+      assert.equal(median(["3", "20"]), 11.5);
+      assert.equal(median(["2", "3", "20"]), 3);
+      assert.equal(median(["20", "3", "2"]), 3);
     }
   }
 });