帮小弟我看个LINQ的函数，万分感谢

帮我看个LINQ的函数，万分感谢

C# code

        // returns the nearest center to the input vector, using the L2 norm        public static double[] NearestCenter(double[] vector, double[][] centers)        {            // written in LINQ to "prove it can be done". easier to see that it is functional, too            return centers.Aggregate(centers[0], (old, cur) => (vector.Select((v, i) => v - old[i])                                                                      .Select(diff => diff * diff)                                                                      .Sum() >                                                                vector.Select((v, i) => v - cur[i])                                                                      .Select(diff => diff * diff)                                                                      .Sum()) ? cur : old);        }

C# code

T Aggregate<T>(this IEnumerable<T> collection, T first, Func<T, T, T> foo){    T old = first;    T r;    foreach (var cur in collection)    {        r = foo(old, cur);        old = cur;    }    return r;}