Translate Linq Aggregate from VB to C#

Question

Hi In the Linq query below values is an array of double. Could some please translate this VB.Net Linq query into C#: Dim Aggreg = Aggregate v In values _ Into Count() _ Sum() _ Sum_Of_Squares = Sum(v * v) Thank you Scott

Subhendu De · Answer

Hi Scott Sorry for delay response. I was working on it. During solving this issue I found a difference between SUM And AGGREGATE. Aggregate --> Returns a custom aggregate of the specified expression as defined by the data provider. Sum --> Returns the sum of all the non-null numeric values specified by the expression evaluated in the given scope. For your solution I prefer to use SUM instead of AGGREGATE. I was more aligned to use AGGREGATE because my motive is to transform your VB.NET code to equivalent C#. Double[] values = new Double[] { 2.2 2.3 3.3 4.1 5.6 }; var Aggreg = new { Count = (from v in values select v).Count() Sum = (from v in values select v).Sum(v => v) Sum_Of_Squares = (from v in values select v).Sum(v=>Math.Pow(v2)) }; Console.WriteLine(Aggreg.Count); Console.WriteLine(Aggreg.Sum); Console.WriteLine(Aggreg.Sum_Of_Squares); Reference Page -> http://msdn.microsoft.com/en-us/library/ms159673%28v=SQL.100%29.aspx Please mark this as answer if it serves your query. Thanks.....

S Lemen · Answer

Hi Subhendu Thank you for your help with the translating the Linq query. However I have a further question or observation. There is a problem with part of the query. The Sum_of_Squares does not yield the correct result. The value of the double ret after the foreach loop does not equal the Aggreg.Sum_Of_Squares but it shoud. Code: double [] values = { 2.2 2.3 3.3 4.1 5.6 }; double ret; var Aggreg = new { Count = ( from v in values select v).Count() Sum = ( from v in values select v).Aggregate((cnt v) => cnt += v) Sum_Of_Squares = ( from v in values select v).Aggregate((cnt v) => cnt += (v * v)) }; foreach ( double v in values) { ret += (v * v); } ret = 69.19 but Aggreg.Sum_Of_Squares = 66.55. I don't know why they are not equal. Thank you for your help Regards Scott

Subhendu De · Answer

Scott I hope the solution works for you. If yes then please accept the answer and if not then let me know. It will help community people to concentrate on other unanswered threads rather than answered threads. It was just a suggestion and not a big deal. Thanks.....

S Lemen · Answer

Got it. Thank you. Scott

Subhendu De · Answer

Double[] values = new Double[] { 1.1 1.2 1.3 1.4 1.5 }; var Aggreg = new { Count = (from v in values select v).Count() Sum = (from v in values select v).Aggregate((cnt v) => cnt += v) Sum_Of_Squares = (from v in values select v).Aggregate((cnt v) => cnt += (v * v)) }; Thanks.....