/*[[
 Name := Keltner Channel
 Author := mteemant
 Notes := Basic Keltner Channel - 
 Separate Window := No
 First Color := Yellow
 First Draw Type := Line
 First Symbol := 217
 Use Second Data := Yes
 Second Color := Yellow
 Second Draw Type := Line
 Second Symbol := 218
]]*/
input: ma_period(12), ma_type(MODE_SMA);
Var: shift(0);
Var: upper_Keltner(0), loopbegin(0), lower_Keltner(0);
Var: avg_3_price(0), diff_price(0),K(0),first(True),;
var: Current_EMA(0), Prev_EMA(0), Diff_EMA(0), prev_EMA_Diff(0);
Variables : bar(0), prevbars(0), start(0), cs(0), prevcs(0),commodt(0);
var: cum_diff_price(0),cum_price(0),sh(0),cnt(0);
 
   
SetLoopCount(0);
If Bars < prevbars Or Bars-prevbars>1 Then first = True;
prevbars = Bars;
If first Then Begin
	// loopbegin prevent couning of counted bars exclude current
	loopbegin = Bars-ma_period-1;
	If ma_type = 1 then Begin         // exponential MA initialization
		loopbegin = Bars-3;
	//	smconst = 2 / (1+ma_period);
		SetIndexValue(Bars-1,Close[Bars-1]);
	End;
	If loopbegin < 0 Then Exit;      // not enough bars for counting
	first = False;
End;

loopbegin = loopbegin+1;             // current bar is to be recounted too
//cum_price = 0;

For shift = loopbegin Downto 0 Begin

print("shift: = ", shift);
//cum_price = 0;
		avg_3_price = 0;
		diff_price = 0;
		For cnt = 0 To ma_period-1 Begin
			avg_3_price = avg_3_price + (H[shift+cnt]+L[shift+cnt]+C[shift+cnt])/3;
			diff_price = diff_price + (H[shift+cnt]-L[shift+cnt]);
		End;
		Current_EMA = avg_3_price/ma_period;
		Diff_EMA = diff_price/ma_period;


print("cum_price: " ,cum_price);
print("Current_EMA: ", Current_EMA);
print("Diff_EMA: ", Diff_EMA);

upper_Keltner = Current_EMA + Diff_EMA;
lower_Keltner = Current_EMA - Diff_EMA;
//Formula#2: 
//NAME: Upper Keltner Band 
//FORMULA: MAvg((H+L+C)/3, Period) + MAvg((H-L), Period)
//Formula#3: 
//NAME: Lower Keltner Band 
//FORMULA: MAvg((H+L+C)/3, Period) - MAvg((H-L), Period)
 
 print("upper_Keltner: ", upper_Keltner);
 print("lower_Keltner: ", lower_Keltner);
 
 SetIndexValue(shift, upper_Keltner);
 SetIndexValue2(shift, lower_Keltner);
 loopbegin = loopbegin-1;
End;