NinjaScript > Language Reference > Indicator Methods >
Directional Movement Index (DMI)
An indicator developed by J. Welles Wilder for identifying when a definable trend is present in an instrument. That is, the DMI tells whether an instrument is trending or not.
... Courtesy of Investopedia
double; Accessing this method via an index value [int barsAgo] returns the indicator value of the referenced bar.
You can view this indicator method source code by selecting the menu Tools > Edit NinjaScript > Indicator within the NinjaTrader Control Center window.