Struggling moving from tradestation to Ninja

[SteveH]

In Tradestation Easy Language you can create user-defined variables to use in the decision tree for trade signals. In TS the process is:
1) Give the variable a name and a default value
2) Specify the calculation of the variable mathematically and/or conditionally.
3) The variable is updated each bar.
3) Use the resultant value in your decision tree.

I cannot figure out how to do this in Ninja Script. When I try I get method group or operand errors.

Can someone point me to some information on how to create user-defined variables that can be used in strategies?

[NinjaTrader_Matthew]

Hello Steve,

Thank you for your post.

We have a reference sample which covers how to create User Defined Variables:

http://www.ninjatrader.com/support/forum/showthread.php?t=5782

Please apply the concepts in this guide and let me know if you run into any trouble.

[SteveH]

OK, tried that and received the following error when compiling " Your strategy likely holds one or more recursive properties......." When I choose to"edit" the recursive properties, it highlights the variable's name (momen) in the properties section:

[Description("")]
[GridCategory("Parameters")]
public double momen
{
get { return momen; }
set { momen = Math.Max(.5, value); }

[NinjaTrader_Matthew]

Hello,

You will need to change the public double to a Captial

[Description("")]
[GridCategory("Parameters")]
[COLOR="Red"]public double Momen
[/COLOR]{
get { return momen; }
set { momen = Math.Max(.5, value); }
}

[SteveH]

Just realized I put "public" instead of "private". When I put private it says the strategy already contains a definition for momen.

[NinjaTrader_Matthew]

You will want it to be Public here, however this public variable should be capitalized.

[SteveH]

When I try to specify the calculations for momen say, close[0] - close[10], I get an error stating "close" is not allowed in the current context.

private double momen = (close[0] - close[10]);

[NinjaTrader_Matthew]

C# is CaSe sensative, so make sure you are calling the close data point by using the captial letter. Additionally, to get the most recent close price, you will want to use bar index of [0]

momen = Close[0] - Close[10];

[SteveH]

Now I get: "An object reference is required for the non-static field, method or property "NinjaTrader.Strategy.StrategyBase.Close.get"

[NinjaTrader_Matthew]

The Close data series needs to be set in the OnBarUpdate() method of your code.

        #region Variables
		// first declare the variable type and name
		private double momen = 0;
       
        #endregion

        protected override void OnBarUpdate()
        {
                        //here in OnBarUpdate you can set the value to the variable
			momen = Close[0] - Close[10];
			
        }

[SteveH]

OK. If I follow the process correctly I need to:
1) Establish the variable in the //User defined variables section
2) Define the variable in the #region Properties section
3) Enter the calculations in the OnBarUpdate section

Correct?

[NinjaTrader_Matthew]

Hello,

Yes, that is correct