Problem with CountIf

[ganbare112]

Hi,

I have a strategy that I'm migrating over from NT7 that works. I use the CountIf function 3 times in the code, when I take these instances out, I have no issues. Is there something wrong with the function call? I've included the code and the error response below.

Thanks!

int countCross3 = CountIf(() => CrossAbove(Close, EMA(44),1),55);
int countCross4 = CountIf(() => CrossAbove(Close, EMA(44),1),55);
CountIf(() => Close[0]-Low[0] >= .75, 8) >=4

Strategy 'MomentumUpTrade': Error on calling 'OnBarUpdate' method on bar 50: condition
Parameter name: 'CountIf' on bar 0 threw exception: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

[NinjaTrader_PaulH]

Hello ganbare112,

Thanks for your post.

Based on the error message I recommend you use a current bar check before accessing the countif statements. Something like:

if (CurrentBar < 55) return;

Reference: http://ninjatrader.com/support/helpG...currentbar.htm

[ganbare112]

Ah yes, I had CurrentBar < 30 but that wasn't enough, thanks so much!

[PaulMohn]

Hello Paul, I have a similar error with countif()

Time Category Message
23/03/2022 15:19:08 Default Indicator 'Testa': Error on calling 'OnBarUpdate' method on bar 11: You are accessing an index with a value that is invalid since it is out-of-range. I.E. accessing a series [barsAgo] with a value of 5 when there are only 4 bars on the chart.

I tried increasing the CurrentBar check but that's not solving the error.

I use countif() with bars series of current bars' Highs and previous bars' Highs (for example).

I'm trying to get something like this

High[0] - High[1] ranges in a list, then count the number for >= 13 Ticks with countif().


Below is a simplified version of my script

namespace NinjaTrader.NinjaScript.Indicators
{
   public class Testa: Indicator
   {

      private Series<double> RangeTopRangeBottom;

      private List<double> listOfSeriesValues, listOfSeriesValuesBarsBack;


    protected override void OnStateChange()
    {
      if (State == State.SetDefaults)
      {
        BarsBack                = 10;
        TopIndex               = 0;
        BottomIndex             = 0;

      }
      else if (State == State.Configure)
      {
      }
      else if (State == State.DataLoaded)
      {
        RangeTopRangeBottom = new Series<double>(this, MaximumBarsLookBack.Infinite);

        listOfSeriesValues = new List<double>();
        listOfSeriesValuesBarsBack = new List<double>();
      }
    }


    protected override void OnBarUpdate()
    {

       if (CurrentBar < BarsBack) return;

       double var1 = CountIf(() => High[TopIndex] - High[BottomIndex] >= 13*TickSize, BarsBack);

       RangeTopRangeBottom[TopIndex] = High[TopIndex] - High[BottomIndex]; 

As you can see I have properties variables

TopIndex and BottomIndex for the indexes, and BarsBack for the Countif() period.

I think I can understand the reason for the error is that at bar 11 Countif() can't access bar 10 High value. Is that the correct reason?
If it is I wonder why it cannot access it since there should be enough bars available.

But then I'm wondering if the CurrentBar check is the cause as it's stating to discard the previous bars from bar 11 and not use their values for calculations.
if that's the cause, I can't understand/guess how to adjust the CurrentBar check for it to take into account the previous Bar's values.
If I increase the number of Bars for the CurrentBar check that doesn't solve the problem.

            if (CurrentBar < BarsBack+1) return; 

Time Category Message
23/03/2022 15:19:08 Default Indicator 'Testa': Error on calling 'OnBarUpdate' method on bar 11: You are accessing an index with a value that is invalid since it is out-of-range. I.E. accessing a series [barsAgo] with a value of 5 when there are only 4 bars on the chart.

Same if I decrease it

            if (CurrentBar < BarsBack-1) return; 

Time Category Message
23/03/2022 15:19:08 Default Indicator 'Testa': Error on calling 'OnBarUpdate' method on bar 9: You are accessing an index with a value that is invalid since it is out-of-range. I.E. accessing a series [barsAgo] with a value of 5 when there are only 4 bars on the chart.

What would be a start for the solution to this error? Thanks!

[NinjaTrader_Kate]

Hello PaulMohn,

Thank you for your reply.

I've plugged the code you provided into an indicator script and run it and do not receive an error. Can you confirm you receive an error running just the code provided in your post?

Thanks in advance; I look forward to assisting you further.

[PaulMohn]

Hello Kate and thanks for the reply. I've isolated further the error line

it occurred on this line lower in the script

listOfSeriesValuesBarsBack = listOfSeriesValues.GetRange(((listOfSeriesValues.Count() - 1) - BarsBack), (BarsBack - 1)); 

I then noticed the line needed correction as

listOfSeriesValuesBarsBack = listOfSeriesValues.GetRange((listOfSeriesValues.Count() - (BarsBack + 1)), (BarsBack)); 

I then tested with

if (CurrentBar <= (BarsBack*2)) return; 

and it removed the error.

Then i tested successively with +1 to + 8 and the error remained until + 9

if (CurrentBar <= (BarsBack+1)) return; 

if (CurrentBar <= (BarsBack+2)) return; 

if (CurrentBar <= (BarsBack+3)) return; 

if (CurrentBar <= (BarsBack+4)) return; 

if (CurrentBar <= (BarsBack+5)) return; 

if (CurrentBar <= (BarsBack+6)) return; 

if (CurrentBar <= (BarsBack+7)) return; 

if (CurrentBar <= (BarsBack+8)) return; 

The error stopped at

if (CurrentBar <= BarsBack+9) return; 

+9 or *2 works

if (CurrentBar <= (BarsBack+9)) return;

listOfSeriesValuesBarsBack = listOfSeriesValues.GetRange((listOfSeriesValues.Count() - (BarsBack + 1)), (BarsBack)); 

if (CurrentBar <= (BarsBack*2)) return;

listOfSeriesValuesBarsBack = listOfSeriesValues.GetRange((listOfSeriesValues.Count() - (BarsBack + 1)), (BarsBack)); 

So the solution seems to be
if (CurrentBar <= BarsBack + (BarsBack-1)) return;

The new simplified working snippet

namespace NinjaTrader.NinjaScript.Indicators
{
   public class Testa: Indicator
   {

      private Series<double> RangeTopRangeBottom;

      private List<double> listOfSeriesValues, lis tOfSeriesValuesBarsBack;


    protected override void OnStateChange()
    {
      if (State == State.SetDefaults)
      {
        BarsBack                = 10;
        TopIndex               = 0;
        BottomIndex             = 0;

      }
      else if (State == State.Configure)
      {
      }
      else if (State == State.DataLoaded)
      {
        RangeTopRangeBottom = new Series<double>(t his, MaximumBarsLookBack.Infinite);

        listOfSeriesValues = new List<double>();
        listOfSeriesValuesBarsBack = new List<doub le>();
      }
    }


    protected override void OnBarUpdate()
    {

       if (CurrentBar < BarsBack) return;

       double var1 = CountIf(() => High[TopIndex] - High[BottomIndex] >= 13*TickSize, BarsBack);

       RangeTopRangeBottom[TopIndex] = High[TopIndex] - High[BottomIndex];


    if (CurrentBar <= BarsBack + (BarsBack-1)) return;

    listOfSeriesValuesBarsBack = listOfSeriesValues.GetRange((listOfSeriesValues.Count() - (BarsBack + 1)), (BarsBack)); 

I'm not sure i understand why it required a BarsBack + (BarsBack-1) Currentbar Check. Do you know why it does? Thanks!

[NinjaTrader_Kate]

Hello PaulMohn,

Thank you for your reply.

In my testing with just the above code I still get an error using if (CurrentBar <= BarsBack + (BarsBack-1)) return;

I suspect this is related to not having assigned any values to listOfSeriesValues at this point in the script and I note that further code has been omitted, so I would not be able to say for sure.

Please let us know if we may be of further assistance to you.

[PaulMohn]

I checked with more scenarii and it returned errors so I increased to

if (CurrentBar <= (BarsBack + (BarsBack*3))) return;


listOfSeriesValuesBarsBack = listOfSeriesValues.GetRange((listOfSeriesValues.Count() - (BarsBack + 1)), (BarsBack)); 

and it seems to work for all cases now. I'll try to ajdust some more and be back asa. Thnaks!