Pattern detection via indicator

[nybangali]

I am trying to create an indicator that detects a pattern of 3 bars with the high of the middle bar is higher than the high of the surrounding 2 bars.
Here is the code, with Overlay set to true and PlotStyle.Dot. I see nothing

if (CurrentBar == 0) {
Upfractal.Set(0);
} else {

if ((High[0] < High[1]) && (High[2] < High[1])) {
Upfractal.Set(High[1]);
} else {Upfractal.Set(0);}

}


I tried overlay set to false, and PlotStyle.Line to see if it paints in the lower panel, but in that case I see a blank panel below.

[NinjaTrader_Dierk]

Whenever you experience something unexpected you should inspect the logs. In your case they will indicate that
High[2]
is the problem, since you need to change your code like this
if (CurrentBar <= 1) {

[nybangali]

Pattern detection via indicator Reply to Thread

Good tip... never thought of looking at the log
Have the following log upon refreshing the chart
"Error on calling the 'OnBarUpdate' method for indicator 'Fractals2' on bar 3: Index was out of range. Must be non-negative and less than the size of the collection."

I did replace the (CurrentBar == 0) with (CurrentBar <= 1) and it gave the above error. With CurrentBar ==0 it just stated "bar 1" instead of "bar 3".

Hoping for another clue.

I have a different question. Who is Ninjatrader targeted to ? The programmer/investor demographic ? You need to get into super duper programming to implement anything beyond the most basic strategies. Is the average trader really into this learning curve? I really appreciate the fast response on this forum, but reading through the other posts, I see you folks do draw the line quite fast.
Don't get me wrong - I get a gut feeling for the power of NT, but having used Metastock for a while, this is far more complex.
Implementing the pattern detection exercise I am trying to do took me 30 seconds to do in Metastock after 2 days of using their experts !

Whenever you experience something unexpected you should inspect the logs. In your case they will indicate that
High[2]
is the problem, since you need to change your code like this
if (CurrentBar <= 1) {

[NinjaTrader_Dierk]

(edited my post)
I suggest starting simple as possible and see where your code below causes the problem. You then could add more logic step-by-step.

On NT: It depends on what you want to do: A good starter is the strategy wizard where you can implement simple strategies. More flexibility comes at the expense of coding strategies/indicators manually.
Unfortunately we do not yet have a wizard for indicators or pattern detection.

[nybangali]

Pattern detection via indicator

re: starting simple as possible...
does it get any simpler than ..
if ((High[0] < High[1]) && (High[2] < High[1])) {
MyIndicator.Set(High[1]);
}
How about this... Can you provide a simple example of a simple historical pattern based indicator? I understand you're not here to code my problems. But I think its a fair question.

This thing takes 10 seconds in Metastock using the expert.
Fine.. so why I am I still struggling with NT ? Because I was using Metastock EOD, and now considering moving to Realtime... one advantage of NT is the cost.. the other is that I need a real time trade execution platform which I don't think Metastock has.

(edited my post)
I suggest starting simple as possible and see where your code below causes the problem. You then could add more logic step-by-step.

On NT: It depends on what you want to do: A good starter is the strategy wizard where you can implement simple strategies. More flexibility comes at the expense of coding strategies/indicators manually.
Unfortunately we do not yet have a wizard for indicators or pattern detection.

[NinjaTrader_Dierk]

This code works perfectly on a wizard generated indicator template:

        protected override void OnBarUpdate()
        {
            if (CurrentBar <= 1) 
                Plot0.Set(0);
            else if (High[0] < High[1] && High[2] < High[1])
                Plot0.Set(High[1]);
            else 
                Plot0.Set(0);
        }

Note: You need to replace Plot0 by the name of your actual plot series you entered in the wizard.

[nybangali]

Pattern detection via indicator

Thank you. This works. And I even figured out to set the Displacement value to -1 manually and save the chart template so that it appears on the actual high bar.
Very nice.

This code works perfectly on a wizard generated indicator template:

        protected override void OnBarUpdate()
        {
            if (CurrentBar <= 1) 
                Plot0.Set(0);
            else if (High[0] < High[1] && High[2] < High[1])
                Plot0.Set(High[1]);
            else 
                Plot0.Set(0);
        }

Note: You need to replace Plot0 by the name of your actual plot series you entered in the wizard.