Bump to v4.1.0.

lodash.mean/index.js

@@ -1,18 +1,78 @@
 /**
- * lodash 4.0.0 (Custom Build) <https://lodash.com/>
+ * lodash (Custom Build) <https://lodash.com/>
  * Build: `lodash modularize exports="npm" -o ./`
- * Copyright 2012-2016 The Dojo Foundation <http://dojofoundation.org/>
+ * Copyright jQuery Foundation and other contributors <https://jquery.org/>
+ * Released under MIT license <https://lodash.com/license>
  * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
- * Copyright 2009-2016 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
- * Available under MIT license <https://lodash.com/license>
+ * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
  */
-var sum = require('lodash.sum');
+
+/** Used as references for various `Number` constants. */
+var NAN = 0 / 0;
+
+/**
+ * The base implementation of `_.mean` and `_.meanBy` without support for
+ * iteratee shorthands.
+ *
+ * @private
+ * @param {Array} array The array to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {number} Returns the mean.
+ */
+function baseMean(array, iteratee) {
+  var length = array ? array.length : 0;
+  return length ? (baseSum(array, iteratee) / length) : NAN;
+}
+
+/**
+ * The base implementation of `_.sum` and `_.sumBy` without support for
+ * iteratee shorthands.
+ *
+ * @private
+ * @param {Array} array The array to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {number} Returns the sum.
+ */
+function baseSum(array, iteratee) {
+  var result,
+      index = -1,
+      length = array.length;
+
+  while (++index < length) {
+    var current = iteratee(array[index]);
+    if (current !== undefined) {
+      result = result === undefined ? current : (result + current);
+    }
+  }
+  return result;
+}
+
+/**
+ * This method returns the first argument it receives.
+ *
+ * @static
+ * @since 0.1.0
+ * @memberOf _
+ * @category Util
+ * @param {*} value Any value.
+ * @returns {*} Returns `value`.
+ * @example
+ *
+ * var object = { 'a': 1 };
+ *
+ * console.log(_.identity(object) === object);
+ * // => true
+ */
+function identity(value) {
+  return value;
+}
 
 /**
  * Computes the mean of the values in `array`.
  *
  * @static
  * @memberOf _
+ * @since 4.0.0
  * @category Math
  * @param {Array} array The array to iterate over.
  * @returns {number} Returns the mean.
@@ -22,7 +82,7 @@ var sum = require('lodash.sum');
  * // => 5
  */
 function mean(array) {
-  return sum(array) / (array ? array.length : 0);
+  return baseMean(array, identity);
 }
 
 module.exports = mean;