Find collection containing the average of several collections with LINQ

Simple (not for me yet I guess) LINQ: I have a List of arrays, and I want to get a collection c开发者_如何学运维ontaining the average of each column. Something like:

var myCollection = new List<double[]>();
myCollection.Add(new []{1,2,3,4,5});
myCollection.Add(new []{3,4,5,6,7});
// Your answer -->     {2,3,4,5,6}

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Like so?

var myCollection = new List<double[]>();
myCollection.Add(new double[]{1,2,3,4,5});
myCollection.Add(new double[]{3,4,5,6,7});

var qry = (from col in Enumerable.Range(0, myCollection.Min(arr => arr.Length))
           select myCollection.Average(arr => arr[col])).ToList();

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Original answer from when the question referred to a "2 dimensional array":

How about (note - you may need to reverse col and row depending on how you choose to orient your data):

int[,] data = {{0,1,2},{3,4,5}};
var qry = (from col in Enumerable.Range(0, data.GetLength(0))
           select new {
              col, avg = Enumerable.Range(0, data.GetLength(1))
                         .Select(row => data[col, row]).Average()
           }).ToList();

foreach(var result in qry) {
    Console.WriteLine("{0}: {1}", result.col, result.avg);
}

Or if you just want the averages (not the anon-type):

var qry = (from col in Enumerable.Range(0, data.GetLength(0))
           select Enumerable.Range(0, data.GetLength(1))
               .Select(row => data[col, row]).Average()).ToList();

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Since you have modified the question, changing the 2 dimensional array to List<double[]>, another solution is:

var result = myCollection.Aggregate((arr1, arr2) => arr1.Zip(arr2, (x, y) => (x + y) / 2).ToArray())