Using Multiple Donchian Lowerband As StopLoss

[wahyu]

I plan to create trading system with stop loss rule as follow:
If buy price less than DonchianLower30 than use DonchianLower30 as stop loss level, unless use DonchianLower20.

DonchianUpper20 =HHV(Ref(H,-1),20);
DonchianLower20 = LLV(Ref(L,-1),20);

DonchianUpper30 =HHV(Ref(H,-1),30);
DonchianLower30 = LLV(Ref(L,-1),30);

Plot(DonchianUpper20,"DU",colorBlue,styleLine);
Plot(DonchianLower20,"DL",colorBlue,styleLine);

Plot(DonchianUpper30,"DU",colorRed,styleLine);
Plot(DonchianLower30,"DL",colorRed,styleLine);
 
Buy = H > DonchianUpper20;
sellpoint = IIf(BuyPrice < DonchianLower30, DonchianLower30, DonchianLower20);
Sell = L < sellpoint;
Buy = ExRem(Buy,Sell);
Sell = ExRem(Sell,Buy);
 
  
/* Plot Buy and Sell Signal Arrows */
PlotShapes(IIf(Buy, shapeUpArrow, shapeNone),colorGreen, 0, L, Offset=-15);
PlotShapes(IIf(Sell, shapeDownArrow, shapeNone),colorRed, 0, L, Offset=-15);

On picture above, sell signal souldn't occur yet because buy price is less than DonchianLower30.
How to fix the code?

[wahyu]

Finally, I found the solution.

Buy = H > DonchianUpper20;
BuyPrice = ValueWhen(Buy, C, 1);
Sell = 0;
titikbuy = 0;

for( i = 1; i < BarCount; i++ )
{

   if( titikbuy == 0 AND Buy[ i ] ) 
   { 
      titikbuy = BuyPrice[ i ];
   }
   else 
   {
	  Buy[ i ] = 0; // remove excess buy signals
   }

   if( titikbuy > 0 AND titikbuy < DonchianLower30[ i ] )
   {
      if(L[i] < DonchianLower30[ i ])
      {
		  Sell[ i ] = 1;
		  SellPrice[ i ] = C[i];
		  titikbuy = 0;
      }
   }
   else
   {
	  if( titikbuy > 0 AND titikbuy >= DonchianLower30[ i ] )
	  {
		  if(L[i] < DonchianLower20[ i ])
		  {
			 Sell[ i ] = 1;
			 SellPrice[ i ] = C[i];
			 titikbuy = 0;
		  }
	  }
   }
 

}

Case closed.

[Pinecone]

I looked at your code yesterday and couldn't see any glaring reason why it did not work.

I would think you shouldn't have to use a for loop in order to get this done. For loops will significantly slow down your code.

Maybe someone can chime in with an even better answer?

[beppe]

@Pinecone, what happens using ValueWhen in the "sellpoint" condition in the OP first formula?
I suggest to add some exploration lines to understand what's going on. What is the BuyPrice at each bar? What should be its value used in that condition?