Linq Array filter or range

Question

Vuples where are you lololol?

using linq i want multilpty to multiply (Aarray1 * Array2) from 2.3 to 2.05 then i want to sum the output array base upon the range , can some help me

Array1[0] = {( 2.00, 1.00 )}   * Array2[0] = {( 2.00, 2.00 )} = 2
Array1[1] = {( 2.01, 2.00 )}   *   Array2[1] = {( 2.01, 3.00 )} = 6
Array1[2] = {( 2.02, 3.00 )} * Array2[2] = {( 2.02, 4.00 )} = 12
Array1[3] = {( 2.03, 4.00 )}   * Array2[3] = {( 2.03, 5.00 )} = 20
Array1[4] = {( 2.04, 5.00 )}   * Array2[4] = {( 2.04, 6.00 )} = 30
Array1[5] = {( 2.05, 6.00 )}   *   Array2[5] = {( 2.05, 7.00 )} = 42
Array1[6] = {( 2.06, 7.00 )}   *   Array2[6] = {( 2.06, 8.00 )} = 56
-----------------------------------------------------------------------



Output[0] = {( 2.03, 20)}
Output[1] = {( 2.04, 30 )}
Output[2] = {( 2.05, 42 )}

double result = Output.Sum();

result = 92

Vulpes · Answer

This should work: using System; using System.Linq; class Program { static void Main() { var Array1 = new double[7][]; Array1[0] = new double[]{ 2.00 1.00 }; Array1[1] = new double[]{ 2.01 2.00 }; Array1[2] = new double[]{ 2.02 3.00 }; Array1[3] = new double[]{ 2.03 4.00 }; Array1[4] = new double[]{ 2.04 5.00 }; Array1[5] = new double[]{ 2.05 6.00 }; Array1[6] = new double[]{ 2.06 7.00 }; var Array2 = new double[7][]; Array2[0] = new double[]{ 2.00 2.00 }; Array2[1] = new double[]{ 2.01 3.00 }; Array2[2] = new double[]{ 2.02 4.00 }; Array2[3] = new double[]{ 2.03 5.00 }; Array2[4] = new double[]{ 2.04 6.00 }; Array2[5] = new double[]{ 2.05 7.00 }; Array2[6] = new double[]{ 2.06 8.00 }; double result = Array1.Where(a => a[0] >= 2.03 && a[0] a[0] >= 2.03 && a[0] a1[1] * a2[1]).Sum(); Console.WriteLine(result); Console.ReadKey(); } }

David Smith · Answer

yea i prefer to break it up i was curious. I have caught on the syntax when adding multiple expressions to one equation to one linq. I am still trying to learn it in the mist.

Vulpes · Answer

When calculating 'result' just replace List1 and List2 with the expressions that have been assigned to them. BTW it's not good coding practice IMO to always cram everything into a single LINQ query. Remember you (or somebody else) may have to maintain this stuff months or years down the line. Whilst LINQ is a powerful tool it can produce some very complex expressions and it may therefore be better to break them up into bits that are easy to understand.

David Smith · Answer

how to put in one linq all together im curious

Vulpes · Answer

OK I've changed List1 and List2 to make this a little easier: var List1 = ArrayDictionary[ArrayType.Array1.ToString()].Where(t => t.Item1 >= 2.03 && t.Item1 var List2 = ArrayDictionary[ArrayType.Array2.ToString()].Where(t => t.Item1 >= 2.03 && t.Item1 double result = List1.Zip(List2 (t1 t2) => t1.Item2 * t2.Item2).Sum()/ List1.Sum(t => t.Item2); Console.WriteLine(result); // 6.13 recurring

David Smith · Answer

The last step is to divide by sum of Array1 from 2.3 to 2.05. So now we have to just add the divide part to the existing linq we have now you did the previous reply Array1[3] = {( 2.03 4.00 )} * Array2[3] = {( 2.03 5.00 )} = 20 Array1[4] = {( 2.04 5.00 )} * Array2[4] = {( 2.04 6.00 )} = 30 Array1[5] = {( 2.05 6.00 )} * Array2[5] = {( 2.05 7.00 )} = 42 -------------------------------------------------------------------- Array1[3] = {( 2.03 4.00 )} Array1[4] = {( 2.04 5.00 )} Array1[5] = {( 2.05 6.00 )} 92 / 15 = 6.1333333333 output = 6.13333333

Vulpes · Answer

Sorry forgot I hadn't attended to this last night :( Here's a version of the program which should work for your ArrayDictionary: using System; using System.Linq; using System.Collections.Generic; enum ArrayType { Array1 Array2 Array3 } class Program { static void Main() { var ArrayDictionary = new Dictionary >>(); var list1 = new List >(); list1.Add(Tuple.Create( 2.00 1.00 )); list1.Add(Tuple.Create( 2.01 2.00 )); list1.Add(Tuple.Create( 2.02 3.00 )); list1.Add(Tuple.Create( 2.03 4.00 )); list1.Add(Tuple.Create( 2.04 5.00 )); list1.Add(Tuple.Create( 2.05 6.00 )); list1.Add(Tuple.Create( 2.06 7.00 )); ArrayDictionary.Add(ArrayType.Array1.ToString() list1); var list2 = new List >(); list2.Add(Tuple.Create( 2.00 2.00 )); list2.Add(Tuple.Create( 2.01 3.00 )); list2.Add(Tuple.Create( 2.02 4.00 )); list2.Add(Tuple.Create( 2.03 5.00 )); list2.Add(Tuple.Create( 2.04 6.00 )); list2.Add(Tuple.Create( 2.05 7.00 )); list2.Add(Tuple.Create( 2.06 8.00 )); ArrayDictionary.Add(ArrayType.Array2.ToString() list2); var List1 = ArrayDictionary[ArrayType.Array1.ToString()]; var List2 = ArrayDictionary[ArrayType.Array2.ToString()]; double result = List1.Where(t => t.Item1 >= 2.03 && t.Item1 t.Item1 >= 2.03 && t.Item1 t1.Item2 * t2.Item2).Sum(); Console.WriteLine(result); Console.ReadKey(); } }

David Smith · Answer

did you come up with anything yet i posted the actually logic i am trying to use in the previous post.

David Smith · Answer

Dictionary >> ArrayDictionary = new Dictionary >>(); for (waveLength = 2.00 index = 0; waveLength { Output[index] = (ArrayDictionary[ArrayType.Array1.ToString()][index].Item2 * ArrayDictionary[ArrayType.Array2.ToString()][index].Item2); ArrayDictionary[ArrayType.ArrayType.ToString()].Add(new Tuple (waveLength Output[index])); } double output = ArrayDictionary[ArrayType.Array1.ToString()].Where(a => a[0] >= LowLimit && a[0] HighLimit).Zip(ArrayDictionary[ArrayType.Array2.ToString()].to.Where(a => a[0] >= 2.03 && a[0] 2.(t1 t2) => t1[1].Item2 * t2[1].Item2).Sum();

Vulpes · Answer

Because Array1[3] and Array1[0] are both arrays of doubles and we want the first element of the latter array. The logic won't work as it stands with ArrayDictionary which - the last time I looked - was a Dictionary  not an array of double arrays. However I notice you're talking again about tuples so if you can tell me how it's currently defined I'll try and adapt the logic to work with that.

David Smith · Answer

So why start at a[0] when the element that i wanted started at Array1[3] and not Array1[0]. Also below my tuple is not working with the logic i am getting a systax error but your console app is working. I am getting error where you see the highlight a[0] double output = ArrayDictionary[ArrayType.Array1.ToString()].Where(a => a[0] >= LowLimit && a[0] HighLimit).Zip(ArrayDictionary[ArrayType.Array1.ToString()].to.Where(a => a[0] >= 2.03 && a[0] 2.(t1 t2) => t1[1].Item2 * t2[1].Item2).Sum();

Vulpes · Answer

Well Array1 and Array2 are both arrays of double arrays. They therefore implement IEnumerable and so (for LINQ purposes) are sequences of double arrays. As each element in the sequence is an array ('a') and we're interested in the first element we therefore use a[0].

David Smith · Answer

Im curious. why did you use a[0] can you explain Where(a => a[0] >= 2.03 && a[0]