Generic Multi-dimensional List

[Shansen]

Ralph,

The output of the below code:

[0][0] = System.Collections.Generic.List`1[System.Int32]
[1][0] = System.Collections.Generic.List`1[System.Int32]
[2][0] = System.Collections.Generic.List`1[System.Int32]
[3][0] = System.Collections.Generic.List`1[System.Int32]

The code:

#region Using declarations
using System.Collections.Generic;
#endregion

namespace NinjaTrader.Indicator
{
    public class TEST2 : Indicator
    {
  #region Variables
      private bool FirstRun = true;
      private int i, j;
      private string sOutput;    
      private List<List<int>> SubList = new List<List<int>>() ;    
      private List<List<List<int>>> MDList = new List<List<List<int>>>();
    #endregion

  protected override void OnBarUpdate()
  {
      if (FirstRun) {
        FirstRun = false;
        
        SubList.Add (new List<int>() {1, 2, 3, 4});
        for (i = 0; i < 4; i++) {
          MDList.Add (new List<List<int>>(SubList));
        }
        
        Print ("Initialized Output");
        sOutput = "";
        for (i = 0; i < MDList.Count; i++) {
          for (j = 0; j < MDList[i].Count; j++) {
            sOutput = sOutput + "[" + i + "]" + "[" + j + "] = " + MDList[i][j] + "\t"; 
          }
          sOutput = sOutput + Environment.NewLine;
        }        
        Print (sOutput);        
      }      
   }
}

Any advice or suggested sources of education would be greatly appreciated.

As always, thanks and regards
Shannon

[Ralph]

Hello Shannon,

I do not use specific sources of informations but I like the link NT_AdamP provided in post #4.

I think your code example operates properly. SubList contains a list with 4 elements. MDList contains the link to SubList four times. Your print statements show that MDList contains 4 elements (SubList) and every element (SubList) contains just 1 element, which is the list with the 4 integer values.

Regards
Ralph

[Shansen]

Ralph & Adam,

Thanks for all your help.

I've reviewed Adam's link from post#4, I've done my best to make it work... and have come up short. The code is wrong and can be seen with the toggling to two different items:
- changing if(RunCount < 1) to "< 2" or higher
- while lower level lists should be added by "D2List.Add (D1List)" this yields incorrect data.
The below code produces the below output which looks good, until the above changes are implemented:

RunCount = 0
D3top = 4, D2top = 3, D1top = 2
D3List.Count 4
D3List.Count[0] 3
D3List.Count[0][0] 2
000 001
010 011
020 021

100 101
110 111
120 121

200 201
210 211
220 221

300 301
310 311
320 321

#region Using declarations
using System.Collections.Generic;
#endregion

// This namespace holds all indicators and is required. Do not change it.
namespace NinjaTrader.Indicator
{
    [Description("Enter the description of your new custom indicator here")]
    public class TEST2 : Indicator
    {
    #region Variables
      private int RunCount = 0;
      private int i, j, k, l, D1top, D2top, D3top;
      private string sOutput;
      private List<string> D1List = new List<string>() ;  
      private List<List<string>> D2List = new List<List<string>>() ;    
      private List<List<List<string>>> D3List = new List<List<List<string>>>();
    #endregion

      protected override void Initialize()
      {
      }

      protected override void OnBarUpdate()
      {
      if (RunCount < 1) {
        Print ("RunCount = " + RunCount);
        RunCount =+ 1;
        
        var rand = new Random();
        D3top = rand.Next(2, 5);
        D2top = rand.Next(2, 5);
        D1top = rand.Next(2, 5);        
        
        Print ("D3top = " + D3top + ", D2top = " + D2top + ", D1top = " + D1top);
        
        D3List.Clear();
        for (i = 0; i < D3top; i++) {
          D2List.Clear();
          for (j = 0; j < D2top; j++) {
            D1List.Clear();
            for (k = 0; k < D1top; k++) {
              D1List.Add (i.ToString()+j.ToString()+k.ToString());
//              Print (D1List[k].ToString() + " = " + i.ToString()+j.ToString()+k.ToString() );
            }
            D2List.Add (new List<string>(D1List)); // D2List.Add (D1List) should be correct but yields incorrect data
          }
          D3List.Add (new List<List<string>> (D2List)); // D3List.Add (D2List)  should be correct but yields incorrect data
        }    
        
        Print ("D3List.Count " + D3List.Count);
        Print ("D3List.Count[0] " + D3List[0].Count);    
        Print ("D3List.Count[0][0] " + D3List[0][0].Count);  
        
        sOutput = "";
        for (i = 0; i < D3List.Count; i++) {
          for (j = 0; j < D3List[i].Count; j++) {
            for (k = 0; k < D3List[i][j].Count; k++) {
              sOutput = sOutput + D3List[i][j][k] + "\t"; 
            }
            sOutput = sOutput + Environment.NewLine;
          }
          sOutput = sOutput + Environment.NewLine;
        }        
        Print (sOutput);  
      } // end RunCount      
    } // end OnBarUpdate

Any last words of wisdom would be welcome. The world of multi-dimensional lists is a little too much for me.

Shannon

[Ralph]

And what is the output when using "<2" or higher?

Regards
Ralph

[Shansen]

Ralph,

Thank you for the reply. The "<2" or higher resulted in an infinite loop. The code "RunCount =+ 1;" was incorrect, the correct code should have been "RunCount += 1;".

I've been working with the example from http://www.dotnetperls.com/nested-list in Visual Studio and have successfully created a three-dimensional(3D) list. The code was subsequently composed in NT7. It is now at the stage where it will successfully build and display a 3DList on OnBarUpdate. But fails to progressively build and display the 3DList where a 2DList is added with each sequential OnBarUpdate.

When building the 3DList with each sequential OnBarUpdate, the first 2DList is repeated as the 2nd and 3rd element of the 3DList.

Please find the TEST3 code attached.

As always any input would be welcome.
Regards
Shannon

[Shansen]

Ralph & the NT team,

Looking into this issue further using Visual Studio, the "TEST3"code which builds a 3DList on a single OnBarUpdate works as expected. The issue of building a 3DList over sequential OnBarUpdates persists, the 1st list is repeated as MDList element 1, 2, & 3.

Perplexingly, inserting a breakpoint on line54 "MDlist.Add(list);" and progressing through the code shows MDList calculate correctly and results in a correct output!! Remove the breakpoint and the issue where the 1st list is repeated as MDList element 1, 2, & 3 presents again!!

Noting I am clearly a novice, respectfully, is there a larger problem I am not aware of with NT7?

Regards
Shannon

[Ralph]

Hello Shannon,

you re-instantiate your random variable with everey invocation of OnBarUpdate() and therefore the creation of the random numbers repeats identically. You should declare the random variable in the indicator's variables section and instantiate it in Initialize(). (protected override void Initialize() {rand = new Random()})

Regards
Ralph