Inheriting Indicator

[francisonweb]

Hi,

I am writing a custom indicator which is inherited from an existing Indicator which is compile in a DLL.

So far my inherited indicator is working as expected. I am trying to add Bollinger Bands but when i do that i receive an error "NinjaTrader.NinjaScript.Indicators.Bollinger is a type but is used like a variable.

This is my code
Bollinger _bb = Bollinger(Volume, 1, 20);

This code works well in my own custom indicator which is inherited from Indicator class, the default way of writing indicators..

I guess i am missing some reference...

Does anyone have suggestion?

Regards,
Francis

[nkhoi]

Hi,

I am writing a custom indicator which is inherited from an existing Indicator which is compile in a DLL.

So far my inherited indicator is working as expected. I am trying to add Bollinger Bands but when i do that i receive an error "NinjaTrader.NinjaScript.Indicators.Bollinger is a type but is used like a variable.

This is my code
Bollinger _bb = Bollinger(Volume, 1, 20);

This code works well in my own custom indicator which is inherited from Indicator class, the default way of writing indicators..

I guess i am missing some reference...

Does anyone have suggestion?

Regards,
Francis

look at post#5

https://ninjatrader.com/support/forum/showthread.php?t=71446

[NinjaTrader_AlanP]

Hello francisonweb,

Thank you for your note.

Without the full code we're unable to test on our end.

If you'd like to upload the full code I can take a look and see if anything jumps out. Or if you'd prefer to email a copy, send to platformsupport[at]ninjatrader[dot]com with Attn: Alan P in the Subject line. Also within the email please include a link to this thread, and the files.

I look forward to your reply.

[francisonweb]

Hi Alan,

There is not much code, BetterVolume Indicator is freely available at http://emini-watch.com/free-stuff/volume-indicator/

This is my code

public class MyBetterVolume : BetterVolume
{
private Bollinger _bb;

protected override void OnStateChange()
{
base.OnStateChange();

if (State == State.SetDefaults)
{
Description = @"MyBetterVolume";
Name = "MyBetterVolume";
Calculate = Calculate.OnBarClose;
IsOverlay = false;
DisplayInDataBox = true;
DrawOnPricePanel = true;
DrawHorizontalGridLines = true;
DrawVerticalGridLines = true;
PaintPriceMarkers = true;
ScaleJustification = NinjaTrader.Gui.Chart.ScaleJustification.Right;
//Disable this property if your indicator requires custom values that cumulate with each new market data event.
//See Help Guide for additional information.
IsSuspendedWhileInactive = true;
}
else if (State == State.Configure)
{
//_bb = new Bollinger();
_bb = Bollinger(Volume, 2, 200);
}
}

protected override void OnBarUpdate()
{
base.OnBarUpdate();
//Add your custom indicator logic here.
}
}

Hope this helps you to replicate the issue.

Regards,
Francis

[NinjaTrader_AlanP]

Hello francisonweb,

Without the file which contains the class BetterVolume, I am unable to test on our end.

What is the advantage of trying to inherit from this BetterVolume class rather than the indicator class?

I look forward to your reply.

[francisonweb]

Hi Alan,

Thanks for replying the BetterVolume indicator is a DLL file with no source code. It can be downloaded from the link in the previous post.I added the DLL has a reference.

I am trying to add Bollinger Bands to the indicator so that i can write some notifications and signals.

Regards,
Francis

[NinjaTrader_AlanP]

Hello francisonweb,

This may be possible however would not be supported.

If you'd like to create signals off the bollinger study you should create a new indicator instance which inherits from the indicator class.

Please let us know if you need further assistance.

[francisonweb]

Hi Alan,

I understand that and i did create a new class everything works but when i add existing indicators like Bollinger or EMA there is compilation error see the error image in my previous post.

When you say it's not supported means you will not assist for such errors?

Regards,
Francis

[NinjaTrader_AlanP]

Hello francisonweb,

I have attached a sample indicator which will reference the Bollinger Band study and set the value of its lower band to a plot.

You could use this as a framework for adding the Bollinger band to an indicator.

Unsupported would apply to having an indicator inherit from your own class rather than the Indicator class, which does not have issue While it may be possible, in the support department at NinjaTrader we do not create, debug, or modify code for our clients. This is so that we can maintain a high level of service for all of our clients.

Please let us know if you need further assistance.

[francisonweb]

Thanks Alan,

I do not see any attachment am i missing something?

Regards,
Francis

[NinjaTrader_AlanP]

Hello francisonweb,

My apologies.

Attached.

[francisonweb]

Hi Alan,

Thanks for the file, i did try the same but it doesn't work. It may be due to the way the Custom Project is compiled and it is not able to lookup other indicators.

Anyways i figured out i am writing the calculation of SMA and StdDev in the indicator file itself and it worked.

Thanks again for taking the efforts to look into this :-)