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Hi MG Ferreira:
I am facing with the problem of "Overflow in Mul() Function".
If overflow occurs in W1 as shown below,
P1:=DR*((T1>0)-(T1<0));
W1:=If(P1=0,If(PREV=0,1000,PREV),SM*PREV+(1-SM)*PREV*(1+PC)*P1);
but the problem disappears in W1 as shown below,
W1:=If(P1=0,If(PREV=0,1000,PREV),SM*PREV+(1-SM)*PREV);
Do you have any suggestion on how to handle this limitation?
Thank you
Eric
--- In equismetastock@xxxxxxxxxxxxxxx, mgf_za_1999 <no_reply@xxxx>
wrote:
> Hi Eric,
>
> At the moment, we are adjusting the weights linearly, by adding or
> subtracting an amount each time they work or don't work. So we
could
> go negative. If we adjust them by adding a percentage, then this
> should not be a problem. Initially we looked at both methods and I
> think I mentioned that the weights may go negative, so we start with
> big ones initially. Try the following
>
> W1 := PREV*(1+PC*P1);
> W2 := PREV*(1+PC*P2);
> W3 := PREV*(1+PC*P2);
>
> Also, maybe add this input, together with the other, at the top:
>
> PC:=Input("Penalise % : ",0,100,10)/100;
> SM:=Input("Smooth % : ",0,100,75)/100;
>
> and change the weights to
>
> W1 := SM*PREV + (1-SM)*PREV*(1+PC*P1);
> W2 := SM*PREV + (1-SM)*PREV*(1+PC*P2);
> W3 := SM*PREV + (1-SM)*PREV*(1+PC*P2);
>
> Then enter a highish value (even 99 or 99.9 is fine) for SM. The
> higher this value, the more smooth the weights will be.
>
> As long as the weights increase, it means they are working! So it
is
> good if they keep on increasing. You can 'reset' them after each
> round, since we only use the relative ones. I am not sure how to do
> this in one variable in MSFL, but it is easy to do by introducing
yet
> another bunch of variables.
>
> Right at the end, change to the following
>
> WA:=W1+W2+W3;
> {Standard weights}
> SW1:=W1/WA;
> SW2:=W2/WA;
> SW3:=W3/WA;
> TA:=SW1*T1+SW2*T2+SW3*T3;
> TA;
>
> Now, SW1 ... SW3 will always be between 0 and 1 and will be the
> percentage of the total signal that comes from the relevant
indicator.
> Thus it does not matter how big W1 becomes, SW1 will be between 0
and
> 1. To make it easier on the plotting, you could change the above to
>
> WA:=W1+W2+W3;
> {Standard weights}
> SW1:=W1/WA*100;
> SW2:=W2/WA*100;
> SW3:=W3/WA*100;
> TA:=(SW1*T1+SW2*T2+SW3*T3)/100;
> TA;
>
> to get SW1 ... SW3 to be between 0 and 100.
>
> Finally, even though SW1 is contained, W1 is not and may run away.
> Again, using something else you would at the end of each loop assign
> SW1 to W1 but I'm not sure this will work in MSFL. If you get
numbers
> that run away, you will pick it up in WA, and we can fix it if it
happens.
>
> Regards
> MG Ferreira
> TsaTsa EOD Programmer and trading model builder
> http://www.ferra4models.com
> http://fun.ferra4models.com
>
>
>
>
>
>
> --- In equismetastock@xxxxxxxxxxxxxxx, chichungchoi <no_reply@xxxx>
wrote:
> > Hi MG Ferreira:
> > Do you receive my email for the results?
> > I found the error of the negative value for the weighting factor,
As
> > I observe each value under the following
> > formula
> >
> > PC = 0.1
> > DR:=(C/Ref(C,-1)-1)*C;
> > P3:=DR*((T3>0)-(T3<0));
> > W3:=If(P3=0,PREV,W3+(P3*(1+PC)));
> >
> > [29 Oct 1997]
> > W3 = 1669.51
> >
> > [30 Oct 1997]
> > C = 9059.9; REF(C,-1) = 10498.2
> > DR = -1241.25 [OK]
> > T3 = -1 [OK]
> > P3 = 1241.25 [OK]
> > W3 = 2365.37 [ERROR]
> >
> > [31 Oct 1997]
> > C = 10765.3; REF(C,-1) = 9059.9
> > DR = 2026.42 [OK]
> > T3 = -0.54499 [OK]
> > P3 = -2026.42 [OK]
> > W3 = -1229.06 [ERROR]
> >
> > ------------------------------------------------------------------
----
> >
> > On the other hands, if changing W3 to PREV, then
> > PC = 0.1
> > DR:=(C/Ref(C,-1)-1)*C;
> > P3:=DR*((T3>0)-(T3<0));
> > W3:=If(P3=0,PREV,PREV+(P3*(1+PC)));
> >
> > [29 Oct 1997]
> > W3 = 28072.17
> >
> > [30 Oct 1997]
> > C = 9059.9; REF(C,-1) = 10498.2
> > DR = -1241.25 [OK]
> > T3 = -1 [OK]
> > P3 = 1241.25 [OK]
> > W3 = 29437.54 [OK]
> >
> > [31 Oct 1997]
> > C = 10765.3; REF(C,-1) = 9059.9
> > DR = 2026.42 [OK]
> > T3 = -0.54499 [OK]
> > P3 = -2026.42 [OK]
> > W3 = 27208.48 [OK]
> >
> > The result looks completely different, and it seems to me, the
> > weighting factors are growing bigger and bigger. Do you have any
idea
> > on how to handle the weight in a huge amount? since the pently
> > function will be less effective to affect the weight as it grows
> > bigger and bigger. How do I know what the maximum level of
weighting
> > factors will be effective in assigning value for learning? such as
> > I don't think the pently function [-2026] will be effective, if
the
> > level of weight is 1,000,000,000.
> > Do you have any suggestion?
> > Thank you
> > Eric :>
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