Arc Tangent OHLC 15 w SAR Stop
This expert needs to have the PowerPivots plus Add-on 

Highlights 

Long 

A2:=Sum((O+H+L+C)/4,15); 
A:=Mov(Mov(Atan(Ref(A2,-15),A2),2,S),2,S); 
B:=Mov(Mov(Atan(A2,Ref(A2,-15)),2,S),2,S); 
Buy:=A<B; 
Sell:=A>B; 
D:=If(BarsSince(Buy)<BarsSince(Sell),-1,If(BarsSince(Buy)>BarsSince(Sell),1,0)); 
LE:=D=-1 AND SAR(.02,.2)<L; 
LX:=D=-1 AND SAR(.02,.2)>L; 
SE:=D=1 AND SAR(.02,.2)>H; 
SX:=D=1 AND SAR(.02,.2)<H; 
F:=ExtFml("PowerPivots.SysEval",LE,LX,SE,SX,"!@#$#@!"); 
F>0 

Short 

A2:=Sum((O+H+L+C)/4,15); 
A:=Mov(Mov(Atan(Ref(A2,-15),A2),2,S),2,S); 
B:=Mov(Mov(Atan(A2,Ref(A2,-15)),2,S),2,S); 
Buy:=A<B; 
Sell:=A>B; 
D:=If(BarsSince(Buy)<BarsSince(Sell),-1,If(BarsSince(Buy)>BarsSince(Sell),1,0)); 
LE:=D=-1 AND SAR(.02,.2)<L; 
LX:=D=-1 AND SAR(.02,.2)>L; 
SE:=D=1 AND SAR(.02,.2)>H; 
SX:=D=1 AND SAR(.02,.2)<H; 
F:=ExtFml("PowerPivots.SysEval",LE,LX,SE,SX,"!@#$#@!"); 
F<0 

Out 

A2:=Sum((O+H+L+C)/4,15); 
A:=Mov(Mov(Atan(Ref(A2,-15),A2),2,S),2,S); 
B:=Mov(Mov(Atan(A2,Ref(A2,-15)),2,S),2,S); 
Buy:=A<B; 
Sell:=A>B; 
D:=If(BarsSince(Buy)<BarsSince(Sell),-1,If(BarsSince(Buy)>BarsSince(Sell),1,0)); 
LE:=D=-1 AND SAR(.02,.2)<L; 
LX:=D=-1 AND SAR(.02,.2)>L; 
SE:=D=1 AND SAR(.02,.2)>H; 
SX:=D=1 AND SAR(.02,.2)<H; 
F:=ExtFml("PowerPivots.SysEval",LE,LX,SE,SX,"!@#$#@!"); 
F=0 

Symbols 

LE 

A2:=Sum((O+H+L+C)/4,15); 
A:=Mov(Mov(Atan(Ref(A2,-15),A2),2,S),2,S); 
B:=Mov(Mov(Atan(A2,Ref(A2,-15)),2,S),2,S); 
Buy:=A<B; 
Sell:=A>B; 
D:=If(BarsSince(Buy)<BarsSince(Sell),-1,If(BarsSince(Buy)>BarsSince(Sell),1,0)); 
LE:=D=-1 AND SAR(.02,.2)<L; 
LX:=D=-1 AND SAR(.02,.2)>L; 
SE:=D=1 AND SAR(.02,.2)>H; 
SX:=D=1 AND SAR(.02,.2)<H; 
F:=ExtFml("PowerPivots.SysEval",LE,LX,SE,SX,"!@#$#@!"); 
F>0 AND Ref(F,-1)<=0 

SE 

A2:=Sum((O+H+L+C)/4,15); 
A:=Mov(Mov(Atan(Ref(A2,-15),A2),2,S),2,S); 
B:=Mov(Mov(Atan(A2,Ref(A2,-15)),2,S),2,S); 
Buy:=A<B; 
Sell:=A>B; 
D:=If(BarsSince(Buy)<BarsSince(Sell),-1,If(BarsSince(Buy)>BarsSince(Sell),1,0)); 
LE:=D=-1 AND SAR(.02,.2)<L; 
LX:=D=-1 AND SAR(.02,.2)>L; 
SE:=D=1 AND SAR(.02,.2)>H; 
SX:=D=1 AND SAR(.02,.2)<H; 
F:=ExtFml("PowerPivots.SysEval",LE,LX,SE,SX,"!@#$#@!"); 
F<0 AND Ref(F,-1)>=0 

LX 

A2:=Sum((O+H+L+C)/4,15); 
A:=Mov(Mov(Atan(Ref(A2,-15),A2),2,S),2,S); 
B:=Mov(Mov(Atan(A2,Ref(A2,-15)),2,S),2,S); 
Buy:=A<B; 
Sell:=A>B; 
D:=If(BarsSince(Buy)<BarsSince(Sell),-1,If(BarsSince(Buy)>BarsSince(Sell),1,0)); 
LE:=D=-1 AND SAR(.02,.2)<L; 
LX:=D=-1 AND SAR(.02,.2)>L; 
SE:=D=1 AND SAR(.02,.2)>H; 
SX:=D=1 AND SAR(.02,.2)<H; 
F:=ExtFml("PowerPivots.SysEval",LE,LX,SE,SX,"!@#$#@!"); 
F=0 AND Ref(F,-1)>0 

SX 

A2:=Sum((O+H+L+C)/4,15); 
A:=Mov(Mov(Atan(Ref(A2,-15),A2),2,S),2,S); 
B:=Mov(Mov(Atan(A2,Ref(A2,-15)),2,S),2,S); 
Buy:=A<B; 
Sell:=A>B; 
D:=If(BarsSince(Buy)<BarsSince(Sell),-1,If(BarsSince(Buy)>BarsSince(Sell),1,0)); 
LE:=D=-1 AND SAR(.02,.2)<L; 
LX:=D=-1 AND SAR(.02,.2)>L; 
SE:=D=1 AND SAR(.02,.2)>H; 
SX:=D=1 AND SAR(.02,.2)<H; 
F:=ExtFml("PowerPivots.SysEval",LE,LX,SE,SX,"!@#$#@!"); 
F=0 AND Ref(F,-1)<0