Here is the code you requested to be translated from Ninjatrader:

// --- settings 
MaintainPercentageOfOwnVolume = .50
TakeOutPercentageOfPreviousBarsVolume = .50
DoesntTradeMoreThanPercentageFromOpen = .20
BarMustBeAtLeastThisPercentageOfATR = .85
// --- end of settings 

result = 0
prevrange=range[1]
if((range * MaintainPercentageOfOwnVolume) < (Close[0] - Low[0])) then // maintain 50% of own volume
if(Close[0] > Low[1] + (prevRange * TakeOutPercentageOfPreviousBarsVolume)) then // takes out 50% of previous bars range
if((Open[0] - Low[0]) < range * DoesntTradeMoreThanPercentageFromOpen) then  // doesn't trade more than 20% of own range lower than open
result = 1 
endif
endif
endif
  
if((range * MaintainPercentageOfOwnVolume) < (High[0] - Close[0])) then // maintain 50% of own volume
if(Close[0] < High[1] - (prevRange * TakeOutPercentageOfPreviousBarsVolume)) then  // takes out 50% of previous bars range
if((High[0] - Open[0]) < range * DoesntTradeMoreThanPercentageFromOpen)then // doesn't trade more than 20% of own range lower than open
result = -1
endif
endif
endif


//final cut  
if(range < (AverageTrueRange[20](close) * BarMustBeAtLeastThisPercentageOfATR)) then 
result=0
endif

if result = 1 then 
drawcandle(open,high,low,close) coloured(0,0,0) bordercolor(0,255,0)
elsif result = -1 then 
drawcandle(open,high,low,close) coloured(139,0,0) bordercolor(255,69,0)
endif 

return

Would be nice to explain how you use it ? Thanks in advance.

bdm-rotation-decision-candle.png