Values Printing but not plotting

[fevs7]

Hi I have a problem I hope someone can help me with.

The attached indicator calculates the y-value of a ray for the current bar from y=mx+b.

For some reason the indicator prints the correct values and draws the dots from the correct bar, but only starts to plot the values a few bars later.

When I try to call up the y plot values from a strategy it says “on bar 11 bject reference not set to an instance of an object.”


I have also tried
if (CurrentBar < 100 )
{
return;
}

in the strategy even though the plot starts earlier but I get the same error.

I would be very grateful if someone could give me a few pointers here.

Thanks!

[koganam]

Hi I have a problem I hope someone can help me with.

The attached indicator calculates the y-value of a ray for the current bar from y=mx+b.

For some reason the indicator prints the correct values and draws the dots from the correct bar, but only starts to plot the values a few bars later.

When I try to call up the y plot values from a strategy it says “on bar 11 bject reference not set to an instance of an object.”


I have also tried
if (CurrentBar < 100 )
{
return;
}

in the strategy even though the plot starts earlier but I get the same error.

I would be very grateful if someone could give me a few pointers here.

Thanks!

Where the Plot starts is controlled by the BarsRequired property.

ref: http://ninjatrader.com/support/helpG...rsrequired.htm

[fevs7]

Where the Plot starts is controlled by the BarsRequired property.

ref: http://ninjatrader.com/support/helpG...rsrequired.htm

Thanks koganam.

That solves the values only plotting a few bars later. I am, however, still getting the same error message when I try to print the values from the strategy "... on bar 11 :Object reference not set to an instance of an object ." I rechecked the indicator and the values are printing for the relevant bars but somehow the strategy does not see it

[fevs7]

Thanks koganam.

That solves the values only plotting a few bars later. I am, however, still getting the same error message when I try to print the values from the strategy "... on bar 11 :Object reference not set to an instance of an object ." I rechecked the indicator and the values are printing for the relevant bars but somehow the strategy does not see it

Just to add to my above post, when I change the indicator to only start calculating from bar 100 the strategy picks up the correct values up to bar 110 and then I get the same error message “on bar 110: Object reference not set to an instance of an object”

[koganam]

Just to add to my above post, when I change the indicator to only start calculating from bar 100 the strategy picks up the correct values up to bar 110 and then I get the same error message “on bar 110: Object reference not set to an instance of an object”

Which means that you are trying to access something that is still null.

Nobody can tell you which line of code is the issue in a vacuum. You will either have to post the code so that we can see what the issue might be, or you have to isolate the errant line yourself.

The easiest way to do the latter is to Print() out checkpoints/values in your code to isolate which statement does not return, then resolve the issue as necessary.

[fevs7]

Which means that you are trying to access something that is still null.

Nobody can tell you which line of code is the issue in a vacuum. You will either have to post the code so that we can see what the issue might be, or you have to isolate the errant line yourself.

The easiest way to do the latter is to Print() out checkpoints/values in your code to isolate which statement does not return, then resolve the issue as necessary.

Hi Koganam
I am still fairly new to this so I thought if the values were printing (which is the case in the indicator ) the null problem was sorted out. Here is the code of the indicator posted previously. Thanks A LOT for your help with this

#region Using declarations
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Xml.Serialization;
using NinjaTrader.Cbi;
using NinjaTrader.Data;
using NinjaTrader.Gui.Chart;
#endregion

// This namespace holds all indicators and is required. Do not change it.
namespace NinjaTrader.Indicator
{
/// <summary>
/// Enter the description of your new custom indicator here
/// </summary>
[Description("Enter the description of your new custom indicator here")]
public class FComboRayLow : Indicator
{
#region Variables

private int period1 = 10; // Default setting for Period1
private int period2 = 5; // Default setting for Period2
private double slope=0;
private double y = 1;





#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;

Add(new Plot(Color.Orange, "low"));
BarsRequired = period1+1 ;


}

/// <summary>
/// Called on each bar update event (incoming tick)
/// </summary>
protected override void OnBarUpdate()
{

if (CurrentBar < BarsRequired ) //based on logic that is used in the BW Pivot Calculations period1+
{
return;
}



if (CurrentBar >= BarsRequired )

{

IRay ray = DrawRay("lows", period1, Low[period1], period2, Low[period2], Color.LimeGreen);

slope=(Low[period2]-Low[period1])/(period1-period2);

y=slope*(ray.Anchor2BarsAgo)+Low[ray.Anchor2BarsAgo];
Value.Set(y);
DrawDot("My dot" + CurrentBar, false, 0, slope*(ray.Anchor2BarsAgo)+Low[ray.Anchor2BarsAgo], Color.Blue);

Print(Time[0]);

Print(y);

Print(Value[0]);




}

}

#region Properties

[Description("Anchor1")]
[GridCategory("Parameters")]
public int Period1
{
get { return period1; }
set { period1 = Math.Max(1, value); }
}

[Description("Anchor2")]
[GridCategory("Parameters")]
public int Period2
{
get { return period2; }
set { period2 = Math.Max(0, value); }
}



[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
}
}

[fevs7]

Hi Koganam
I am still fairly new to this so I thought if the values were printing (which is the case in the indicator ) the null problem was sorted out. Here is the code of the indicator posted previously. Thanks A LOT for your help with this

#region Using declarations
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Xml.Serialization;
using NinjaTrader.Cbi;
using NinjaTrader.Data;
using NinjaTrader.Gui.Chart;
#endregion

// This namespace holds all indicators and is required. Do not change it.
namespace NinjaTrader.Indicator
{
/// <summary>
/// Enter the description of your new custom indicator here
/// </summary>
[Description("Enter the description of your new custom indicator here")]
public class FComboRayLow : Indicator
{
#region Variables

private int period1 = 10; // Default setting for Period1
private int period2 = 5; // Default setting for Period2
private double slope=0;
private double y = 1;





#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;

Add(new Plot(Color.Orange, "low"));
BarsRequired = period1+1 ;


}

/// <summary>
/// Called on each bar update event (incoming tick)
/// </summary>
protected override void OnBarUpdate()
{

if (CurrentBar < BarsRequired ) //based on logic that is used in the BW Pivot Calculations period1+
{
return;
}



if (CurrentBar >= BarsRequired )

{

IRay ray = DrawRay("lows", period1, Low[period1], period2, Low[period2], Color.LimeGreen);

slope=(Low[period2]-Low[period1])/(period1-period2);

y=slope*(ray.Anchor2BarsAgo)+Low[ray.Anchor2BarsAgo];
Value.Set(y);
DrawDot("My dot" + CurrentBar, false, 0, slope*(ray.Anchor2BarsAgo)+Low[ray.Anchor2BarsAgo], Color.Blue);

Print(Time[0]);

Print(y);

Print(Value[0]);




}

}

#region Properties

[Description("Anchor1")]
[GridCategory("Parameters")]
public int Period1
{
get { return period1; }
set { period1 = Math.Max(1, value); }
}

[Description("Anchor2")]
[GridCategory("Parameters")]
public int Period2
{
get { return period2; }
set { period2 = Math.Max(0, value); }
}



[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
}
}

Here is the code from the strategy

// This namespace holds all strategies and is required. Do not change it.
namespace NinjaTrader.Strategy
{
/// <summary>
/// Enter the description of your strategy here
/// </summary>
[Description("Enter the description of your strategy here")]
public class FComboTrendlineDiv : Strategy
{
#region Variables
// Wizard generated variables
private int myInput0 = 1; // Default setting for MyInput0
// User defined variables (add any user defined variables below)
#endregion

/// <summary>
/// This method is used to configure the strategy and is called once before any strategy method is called.
/// </summary>
protected override void Initialize()
{
CalculateOnBarClose = true;
BarsRequired=11;
}

/// <summary>
/// Called on each bar update event (incoming tick)
/// </summary>
protected override void OnBarUpdate()
{



if (CurrentBar<100
) //based on logic that is used in the BW Pivot Calculations
{
return;
}




Print(Time[0]);


Print(FComboRayLow(10, 5).Plot0[0] );



}

[koganam]

Here is the code from the strategy

// This namespace holds all strategies and is required. Do not change it.
namespace NinjaTrader.Strategy
{
/// <summary>
/// Enter the description of your strategy here
/// </summary>
[Description("Enter the description of your strategy here")]
public class FComboTrendlineDiv : Strategy
{
#region Variables
// Wizard generated variables
private int myInput0 = 1; // Default setting for MyInput0
// User defined variables (add any user defined variables below)
#endregion

/// <summary>
/// This method is used to configure the strategy and is called once before any strategy method is called.
/// </summary>
protected override void Initialize()
{
CalculateOnBarClose = true;
BarsRequired=11;
}

/// <summary>
/// Called on each bar update event (incoming tick)
/// </summary>
protected override void OnBarUpdate()
{



if (CurrentBar<100
) //based on logic that is used in the BW Pivot Calculations
{
return;
}




Print(Time[0]);


Print(FComboRayLow(10, 5).Plot0[0] );



}

You do not have a "Plot0" in your indicator code, so "Plot0" does not exist. If you try to access a non-existent public property's value, you get an object access violation. In this case, you are being told that no value was assigned to Plot0, (which as you never defined it, cannot exist, and so, of course, was not assigned).

You can either address the Plot by its correct name that you gave it in the indicator or you can use the base identifier, Plots[0], the latter of which, makes your syntax:

Print(FComboRayLow(10, 5).Plots[0][0] );

[fevs7]

You do not have a "Plot0" in your indicator code, so "Plot0" does not exist. If you try to access a non-existent public property's value, you get an object access violation. In this case, you are being told that no value was assigned to Plot0, (which as you never defined it, cannot exist, and so, of course, was not assigned).

You can either address the Plot by its correct name that you gave it in the indicator or you can use the base identifier, Plots[0], the latter of which, makes your syntax:

Print(FComboRayLow(10, 5).Plots[0][0] );

Hi Koganam
If I print ---- Print(Plot0[0])in the indicator; it prints the correct values at the correct times so I suppose that was why I thought it was correctly defined.

I currently have Plot0 under the properties section as

[Browsable(false)]
[XmlIgnore()]
public DataSeries Plot0
{
get { return Values[0]; }
}

I got that from looking at other indicators but I suppose I am missing something obvious.
There are a few more elements to the indicator. Could you perhaps give me a hint as to how to get it correctly defined and then I will apply it to the rest?

Cheers!

[NinjaTrader_PatrickH]

Hello fevs7,

Thank you for your post.

The only thing you need to do concerning your first post is setting BarsRequired to 0 in Initialize(). This should correct any errors you see.

        protected override void Initialize()
        {

            Overlay				= true;		
						
			Add(new Plot(Color.Orange, "low"));
			
			[B]BarsRequired = 0;[/B]

        }

[fevs7]

Hello fevs7,

Thank you for your post.

The only thing you need to do concerning your first post is setting BarsRequired to 0 in Initialize(). This should correct any errors you see.

        protected override void Initialize()
        {

            Overlay				= true;		
						
			Add(new Plot(Color.Orange, "low"));
			
			[B]BarsRequired = 0;[/B]

        }

Hi Patrick

Thanks for your post. The real problem I have is that I am not able to get access to the values of Plot0 (so the yValue) in a strategy. Initially I thought it was because it was not plotting but now I think it might be something else.

Plot0 prints correctly in the indicator (Print(Plot0[0])

but when I try to print it in a strategy (Print(FComboRayLow(10, 5).Plot0[0])

it says "on bar 11 :Object reference not set to an instance of an object ." and prints a value of 0.

If I set the indicator to only start calculating from bar 100, the strategy prints the correct value up to bar 110 and then I get the same error message.

If you could steer me in the right direction that would be awesome

[fevs7]

apologies for all the emoticons- I still need to switch the auto inclusion off

[NinjaTrader_PatrickH]

Hello fevs7,

Thank you for your response.

Can you attach both the calling strategy and the updated indicator to your response?

[fevs7]

Hello fevs7,

Thank you for your response.

Can you attach both the calling strategy and the updated indicator to your response?

Attached... Thanks.

[NinjaTrader_PatrickH]

Hello fevs7,

Thank you for your response.

The strategy does not add the indicator to the chart and the indicator never draws anything if not added to the chart. So Y is not valid until the ray is drawn.

You will need to add the indicator in Initialize() to correct this:

        protected override void Initialize()
        {
			Add(FComboRayLow(10, 5));
            CalculateOnBarClose =true;
        }

        protected override void OnBarUpdate()
        {
            // Condition set 1
            if (CurrentBar>100)
            {
				
				Print("s"+ FComboRayLow(10, 5).Plot0[0]);
				
            }
        }