How to index[] a variable in a formula?

[baqer110]

Hi!
Is there anyway to index[] a variable?
Like you can index data series High[0], High[-1] etc.
By creating new data series it works for positive index value in "do loop"
But negative index value in "do loop" crashes ninjatrader
Your response will be appreciated

[NinjaTrader_PatrickH]

Hello baqer110,

Thank you for your post.

It is possible and should not crash NinjaTrader. Can you provide the example that crashed NinjaTrader in a do loop?

[baqer110]

Hello baqer110,

Thank you for your post.

It is possible and should not crash NinjaTrader. Can you provide the example that crashed NinjaTrader in a do loop?

Hi!
thanks a lot
Again it relates to High /Low as per our previous thread
In the example below the first do loop works well.
But the 2nd do loop, which I have blocked, if I unblock it NT crashes. No error during compilation

// This namespace holds all indicators and is required. Do not change it.
namespace NinjaTrader.Indicator
{
/// <summary>
/// shows medium term High
/// </summary>
[Description("shows medium term High")]
public class FactoralMTH : Indicator
{
#region Variables
// Wizard generated variables
// User defined variables (add any user defined variables below)
private DataSeries mydataseries;
#endregion

/// <summary>
/// This method is used to configure the indicator and is called once before any bar data is loaded.
/// </summary>
protected override void Initialize()
{

Overlay = true;
mydataseries = new DataSeries(this);
}

/// <summary>
/// Called on each bar update event (incoming tick)
/// </summary>
protected override void OnBarUpdate()
{
if (CurrentBar < 10 )
return;
double a = 0;
double b = 0;

if(High[0] > High[1] && High[0] > High[2] && High[0] > High[-1] && High[0] > High[-2])
a = High[0];


DrawArrowDown(a.ToString(), true, 0, High[0] + TickSize, Color.Red);//short term high

if (Low[0] < Low[1] && Low[0] < Low[2] && Low[0] < Low[-1] && Low[0] < Low[-2])
b = Low[0];

DrawArrowUp(b.ToString(), true, 0, Low[0] - TickSize, Color.Green);//short term low


mydataseries.Set(a);

if (CurrentBar < 100)
return;

int count = 0;// for medium term high
do // this loop works fine and gives left side short term High
{
count = count + 1;
}
while (mydataseries[count] == 0 );

int count1 = 0;
int myno = 0;
/*do// this loop does not work even though ensured to be finite(no complitation error but NT crashes) - //this is for right side short term high
{
myno = myno + 1;
count1 = count1 - 1;
}
while (mydataseries[count1] == 0 && myno <= 50) ;*/

if (mydataseries[0] > mydataseries[count] && mydataseries[0] > mydataseries[-count1])//no problem with this

DrawText(mydataseries[0].ToString(),"MTH", 0, High[0] + 8, Color.Red);

}

#region Properties
[Browsable(false)] // this line prevents the data series from being displayed in the indicator properties dialog, do not remove
[XmlIgnore()] // this line ensures that the indicator can be saved/recovered as part of a chart template, do not remove
public DataSeries Plot0
{
get { return Values[0]; }
}

#endregion
}
}

[NinjaTrader_PatrickH]

In the do loop it looks to see if the value of count1 is 0, yet this value is being decremented from 0 immediately. I am not 100% sure why this causes an issue however, I am able to resolve it simply by removing the check for equals 0. For example:

			int count1 = 0;	
			int myno = 0;	
			do// this loop does not work even though ensured to be finite(no complitation error but NT crashes) - //this is for right side short term high 
			{
			myno = myno + 1;
			count1 = count1 - 1;
			}
			// mydataseries[count1] == 0 && 
			while (myno <= 50) ;

[baqer110]

In the do loop it looks to see if the value of count1 is 0, yet this value is being decremented from 0 immediately. I am not 100% sure why this causes an issue however, I am able to resolve it simply by removing the check for equals 0. For example:

			int count1 = 0;	
			int myno = 0;	
			do// this loop does not work even though ensured to be finite(no complitation error but NT crashes) - //this is for right side short term high 
			{
			myno = myno + 1;
			count1 = count1 - 1;
			}
			// mydataseries[count1] == 0 && 
			while (myno <= 50) ;

Hi!
If you take out (mydataseries == 0) is as good as take out loop
Conclusion is that NT charting platform can not handle negative indexing in loop. This is a lacuna if you don't like to call it a bug. I never had any problem with negative indexing in any other charting platform.
As I had pointed out in other thread, it even causes problem in conditional statement 'if' when used at very beginning.

[NinjaTrader_PatrickH]

You are correct in that a negative index cannot be used, and that is why the do while fails.
However, you can loop with negatives as long as you do not use the negative for an index in a Data Series.