TheLark

The Lark: Directional Movement Index

An open source version of the DMI. Mostly published for other scripters to modify.
Typical useage: http://www.investopedia.com/articles/tec...
Open-source script

In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.

Disclaimer

The information and publications are not meant to be, and do not constitute, financial, investment, trading, or other types of advice or recommendations supplied or endorsed by TradingView. Read more in the Terms of Use.

Want to use this script on a chart?
study(title="TheLark: Directional Movement Index", shorttitle="DMI_LK", overlay=false)

        //•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•//   
        //                                             //
        //        OPEN SOURCE DMI BY THELARK           //
        //                 ~ 8-3-14 ~                 //
        //                                             //
        //                     •/•                     //
        //                                             //
        //    https://www.tradingview.com/u/TheLark    //
        //                                             //
        //•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•/•//

// This is an open source version of the DMI or Directional Movement Index that is provided by Trading View.
// I made this mostly for other scripters to be able to modify and use, but it also helps with transparency,
// and proves that TV uses the correct Wells Wilder MA, and DMI. 

// More to come from me and modified DMI's :)

// Wells Wilders MA
wwma(l,p) =>
    wwma = (nz(wwma[1]) * (l - 1) + p) / l

// Inputs
length = input(14)

// Calc
hiDiff = high - high[1]
loDiff = low[1] - low
plusDM = (hiDiff > loDiff) and (hiDiff > 0) ? hiDiff : 0
minusDM = (loDiff > hiDiff) and (loDiff > 0) ? loDiff : 0
ATR = wwma(length, tr)
PlusDI = 100 * wwma(length,plusDM) / ATR
MinusDI = 100 * wwma(length,minusDM) / ATR
DX = (PlusDI + MinusDI > 0) ? 100 * (abs(PlusDI - MinusDI) / (PlusDI + MinusDI)) : 0

// Plots
plot(wwma(length,DX),color=#FF006E,title="DX")
plot(PlusDI, color=#0EAAEF,title="DI+")
plot(MinusDI,color=orange,title="DI-")