Override Plot

[I_Quant]

Hi

Quite a while back Roonius posted a simple Plot Override indicator that showed 12 static lines printed into the right margin using Plot Override. (I can't find that explicit post again, sorry). I understand how the Plot Override is working but I can't figure out how it is actually invoked.

There is an OnBarUpdate() but it has no statements in it. There is an Initialize where the pens and brushes are defined. But that's it. The lines are made to show by selecting a user parameter to "true" and it all works beautifully, But I don't see how the Plot is "called".

Can anyone shed any light on this, and/or point me in the direction of the C# explanation of this behaviour?

thanks in advance

[koganam]

Originally Posted by I_Quant

Hi

Quite a while back Roonius posted a simple Plot Override indicator that showed 12 static lines printed into the right margin using Plot Override. (I can't find that explicit post again, sorry). I understand how the Plot Override is working but I can't figure out how it is actually invoked.

There is an OnBarUpdate() but it has no statements in it. There is an Initialize where the pens and brushes are defined. But that's it. The lines are made to show by selecting a user parameter to "true" and it all works beautifully, But I don't see how the Plot is "called".

Can anyone shed any light on this, and/or point me in the direction of the C# explanation of this behaviour?

thanks in advance

There is a Plot() function that is called by default on OnBarUpdate or chart refresh. You can define your own Plot() routine to override the default function. IOW, all you have to do to use a custom Plot() function is to specify said Plot() function as an override.

There is no Plot() statement in the OnBarUpdate() event handler, because the code was written to call the default Plot() function. It is just like any other event handler/function, where you can define a new function that calls another function, so that the new function when called shows no explicit call to the called function.

[I_Quant]

many thanks for the explanation Koganam.

I'm sure with a bit more C# experience I will understand it, lol. I get the gist though, many thanks.

Can I mix this type of plot override with the usual Ninja Plot functions ? for example I would like to show 3 or 4 Ninja plots together with my own custom label plots... say by "Calling" specific instances of the custom label plot under certain circumstances.

(Edit: I will leave that question in to provide context but I think I see the answer is that I can do anything providing my C# skills are up to the mark! unlucky me then :-)

However may I ask where the arguments for the Plot Override are created?
public override void Plot(Graphics graphics, Rectangle bounds, double min, double max)

The reason I ask is so that if I create my own customPlot( arguments ) I know how to create the bounds, min and max values ...

thanks again

your help is appreciated.

[koganam]

Originally Posted by I_Quant

many thanks for the explanation Koganam.

I'm sure with a bit more C# experience I will understand it, lol. I get the gist though, many thanks.

Can I mix this type of plot override with the usual Ninja Plot functions ? for example I would like to show 3 or 4 Ninja plots together with my own custom label plots... say by "Calling" specific instances of the custom label plot under certain circumstances.

(Edit: I will leave that question in to provide context but I think I see the answer is that I can do anything providing my C# skills are up to the mark! unlucky me then :-)

However may I ask where the arguments for the Plot Override are created?
public override void Plot(Graphics graphics, Rectangle bounds, double min, double max)

The reason I ask is so that if I create my own customPlot( arguments ) I know how to create the bounds, min and max values ...

thanks again

your help is appreciated.

That may not really be necessary, as bounds, max and min are defined properties of the chart. However, if you want to see some examples of custom Plots, NT itself ships with a CustomPlotSample.cs file. There are other examples in pivots.cs, pricealert.cs, regressionchannel.cs, and a few others besides.