Bollinger Bands

["Von Hef" <VonHef@xxxxxxxxxx>]

 In the Oct issue of "Futures" there is an article written by
Dennis McNicholl called "Better Bollinger Bands". In his 
article he describes how in a trending market the center
band of the B.B. will shift away from the "mean" value of
the price, and that the two outer bands will shift outward
to such an extent that the envelope loses its utility as a
volatility gauge (these are his words... not mine). 
 As usual "Futures" only posted the TradeStation code,
so this is my conversion from it. He called the Indicator
"Denvelope", and it runs the bands much closer.....
similar to "Standard Error Bands".

  {Denvelope}
  {Better Bollinger Bands}
Lb:=Input("Look-Back Period ?",3,100,20);
De:=Input("Band Deviation ?",.5,3,2);
Alp:=2/(Lb+1);
Mt:=Alp*CLOSE+(1-Alp)*PREV;
Ut:=Alp*Mt+(1-Alp)*PREV;
Dt:=((2-Alp)*Mt-Ut)/(1-Alp);
mt2:=Alp*Abs(C-Dt)+(1-Alp)*PREV;
ut2:=Alp*mt2+(1-alp)*PREV;
dt2:=((2-Alp)*mt2-ut2)/(1-Alp);
But:=Dt+de*dt2;
Blt:=Dt-de*dt2;
But;
Dt;
Blt;


 Best wishes,
               Adam Hefner.
 e-mail:  VonHef@xxxxxxxxxx

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