индикатор EMA

--[[
EMA template
--]]
Settings=              
        {                          
            Name = "EMA",   -- indicator name
            ln=20,               -- period		
            line=                                     
                {                               
                    {  
                        Name = "EMA",
                        Type =TYPE_LINE,
                        Width = 1,
                        Color = RGB(0,0,255)
                    }					
                }
       }


function Init()
  ema = {}

  return 1
end


function OnCalculate(index)
  
  ln = Settings.ln 
  if index-1 < 1 then 
    ema[index] = C(index)
  else 
    ema[index] = (ema[index-1]*(ln-1) + C(index))/ln
  end 
 
  return ema[index]

end