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Tomasz,
Perfect, BRAVO!!
a good example to add in the help files...
Stephane,
> This is not recursion but ITERATION.
> PREV in metastock is not the value of some funciton but
> just previous value of array (like in EMA formulation).
>
> What is more: even if some algorithm is recursive it can be
> always rewriten to iterational form (there is a proof for this in
computer science)
>
> As for the question below, of course it can be written using loops
> (as any other algorithm).
>
> BTW: Metastock people have very interesting habit of repeating
> code everywhere and not using variables at all (that's probably
> due to the 20 variable limit that metastock has)
>
> We would need to 'unwind' this bad coding practice:
>
> Original:
> If(LinearReg(C,13)>PREV,If(LinearReg(C,13)-(ATR(13)*2.5)>
> PREV,LinearReg(C,13)-(ATR(13)*2.5),PREV),LinearReg(C,13));
>
> So, we have LinearReg(C,13) in this formula mentioned 4 times and
> ATR(13) mentioned 2 times.
>
> So let us replace this with variables :
>
> myLR = LinearReg( C, 13 );
> myATR = ATR( 13 );
>
> result =
> If( myLR > PREV,
> If( myLR - 2.5 * myATR > PREV,
> myLR - 2.5 * myATR,
> PREV ),
> myLR );
>
> Now let's rewrite to AFL native loops:
>
> myLR = LinearReg( C, 13 );
> myATR = ATR( 13 );
>
> result[ 0 ] = myLR[ 0 ];
> for( i = 1 ; i < BarCount; i++ )
> {
> if( myLR[ i ] > result[ i - 1 ] )
> {
> temp = myLR[ i ] - 2.5 * myATR[ i ];
>
> if( temp > result[ i - 1 ] ) result[ i ] = temp;
> else result[ i ] = result[
i - 1 ];
> }
> else
> result[ i ] = myLR[ i ];
> }
>
> Graph0=result;
>
> Graph1=Close;
>
> This shows "DIRECT" rewriting of the formula. Resulting AFL code is
100+ times faster than Metastock code.
>
>
> Best regards,
> Tomasz Janeczko
> amibroker.com
> ----- Original Message -----
> From: "Stephane Carrasset" <nenapacwanfr@xxxx>
> To: <amibroker@xxxxxxxxxxxxxxx>
> Sent: Tuesday, July 29, 2003 3:16 PM
> Subject: [amibroker] Re: Translation into AFL
>
>
> > Hello,
> > I ask to me if recursion is not supported ( a function call itself
> > from within itself) is it possible to get this formula below (
with
> > PREV) in pure AFL with loops?
> >
> > stephane
> >
> > In amibroker@xxxxxxxxxxxxxxx, "Anthony Faragasso" <ajf1111@xxxx>
> > wrote:
> > > If(LinearReg(C,13)>PREV,If(LinearReg(C,13)-(ATR(13)*2.5)>
> > > PREV,LinearReg(C,13)-(ATR(13)*2.5),PREV),LinearReg(C,13));
> > >
> > >
> > > x=IIf(LinearReg(C,13) > Ref(LinearReg(C,13),-1),
> > > IIf(LinearReg(C,13)-(ATR(13)*2.5)>Ref(LinearReg(C,13)-(ATR(13)
> > *2.5),-1),Line
> > > arReg(C,13)-(ATR(13)*2.5),Ref(LinearReg(C,13)-(ATR(13)*2.5),-
> > 1)),LinearReg(C
> > > ,13));
> > >
> > >
> > > ---
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> >
> >
> > Send BUG REPORTS to bugs@xxxx
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