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StringSeries Class

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Definition
A StringSeries is a special type of data structure that holds a series of string values and always contains the same number of elements as bars in a chart. See the DataSeries Class for related information.

 

Creating StringSeries Objects

To create a StringSeries object:

 

1.Define a variable ("myStringSeries" used in this example) of type StringSeries that will hold a StringSeries object
2.In the Initialize() method, create a new StringSeries object and assign it to the "myStringSeries" variable

 

#region Variables
private StringSeries myStringSeries; // Define a StringSeries variable
#endregion

 

// Create a StringSeries object and assign it to the variable
protected override void Initialize()
{
    myStringSeries = new StringSeries(this); // "this" refers to the indicator, or strategy
                                             // itself. This syncs the StringSeries object
                                             // to historical data bars
}

 

* StringSeries objects can be used on supplementary series in a multi-time frame and instrument strategy. Please see our support forum NinjaScript reference samples section for further information.

 

Note: By default NinjaTrader limits the number of values stored for StringSeries objects to 256. This drastically improves memory performance by not holding onto old values that are generally not needed. Should you need more values than the last 256 please be sure to create the StringSeries object so that it stores all values instead through the use of the MaximumBarsLookBack property.

 

#region Variables
private StringSeries myStringSeries; // Define a StringSeries variable
#endregion

 

// Create a StringSeries object and assign it to the variable
protected override void Initialize()
{

    // MaximumBarsLookBack determines how many values the StringSeries will have access to
    myStringSeries = new StringSeries(this, MaximumBarsLookBack.Infinite);
}

 

Setting Values - StringSeries.Set() & StringSeries.Reset()
You can set value (plug in a value) into a StringSeries object by calling the Set() method.

 

StringSeries.Set(string value)

Setting a value on a StringSeries object is automatically aligned to the current bar being evaluated. This ensures values across all StringSeries objects are always in sync by the CurrentBar index. The following code samples demonstrates calculating the range of each bar and storing the value in a StringSeries object.

 

protected override void OnBarUpdate()
{
    // Just store some text
    myStringSeries.Set(CurrentBar.ToString());
}

 

StringSeries.Set(int barsAgo, string value)
You can also set the value for historical bars by including a "barsAgo" value that represents the number of bars ago that you want the string value to be stored at.

 

Calling the Reset() method is unique and can be very powerful for custom indicator development. StringSeries objects can hold null values which simply means that you do not want to store a value for the current bar. Reset() will reset the current index value to null.

 

 

Checking for Valid Values
It is possible that you may use a StringSeries object but decide not to set a value for a specific bar. However, you should not try to access a StringSeries value that has not been set. Internally, a dummy value does exists, but you want to check to see if it was a valid value that you set before trying to access it for use in your calculations.

 

StringSeries.ContainsValue(int barsAgo)
Returns a true or false value.

 

 

Getting Values
You can access StringSeries object values using the syntax StringSeries[int barsAgo] where barsAgo represents the data value n number of bars ago.

 

protected override void OnBarUpdate()
{
    // Prints the current and last bar value
    Print("The values are " + myStringSeries[0] + " " + myStringSeries[1]);
}