Hi wabbit,

Thank you for you reply. Actually what i want to do is to build my own zigzag to find the recent high and low, just like PeakBars. I don't want to use the build in zigzag so i try to do it myself

percentage:=3;

{Determine whether it is a rising trend or falling trend, 1= rising, -1=falling}
trend:=
If(PREV=1,
If((ref(recenthigh, -1)-C)*100/(ref(recenthigh, -1)+0.0001)<percentage,
PREV,
-1
),
If((C-ref(recentlow, -1))*100/(ref(recentlow, -1)+0.0001)<percentage,
PREV,
1
)
);

{Find the recent low}
recentlow:= (Cum(1)=1)*C+
If(trend=-1),
If(Ref(trend, -1)=1,
C,
If(C<PREV,
C,
PREV
)
),
PREV
);

{Find the recent high}
recenthigh:= (Cum(1)=1)*C+
If(trend=1),
If(Ref(trend, -1)=-1,
C,
If(C>PREV,
C,
PREV
)
),
PREV
);

Here trend needs recenthigh and recentlow, and recenthigh and recentlow needs trends. That's what i mean multiple reference. If I am not allowed to write something like this, then what can i do if I want to write something like zigzag?

Thank you!
Thomas