Hi,
Unlike C, you can almost always accomplish your task by avoiding loops!
Refer to http://www.amibroker.com/guide/h_understandafl.html
<http://www.amibroker.com/guide/h_understandafl.html> for an
explanation of how AFL works.
EMA1 = EMA(C, 10);
EMA2 = EMA(C, 200);
Buycross = Cross(EMA1, EMA2);
Counter = Cum(Buycross);
Triples = Cross(Counter % 3 == 0, 0);
Plot(EMA1,"EMA10", colorRed,styleLine);
Plot(EMA2,"EMA20",colorBlue,styleLine);
Plot(Triples, "Triples", colorGreen, styleOwnScale | styleHistogram);
Mike
--- In amibroker@yahoogroups.com, "m.kuschel31" <m.kusche...@...> wrote:
>
> Hi,
>
> I'm used to programming C during my years in university, but it's been
a while and by all means, I'm not an expert. I've been seriously working
on this for a couple of days and I cannot get a grip on it. I went
through the tutorials, references, etc.
>
> What I am trying to accomplish is rather simple:
>
> Count the number of EMA crossovers (upcross in this case), create an
array that's 1 at multiples of 3 corssovers(so to say after each 3rd
crossover array=1), otherwise the array is 0.
>
> Well, it goes like this:
>
> EMA1=EMA(C,10);
> EMA2=EMA(C,200);
> Plot(EMA1,"EMA10", colorRed,styleLine);
> Plot(EMA2,"EMA20",colorBlue,styleLine);
>
> Buycross[0]=0;
> exit[0]=0;
>
> threshold=3;
> multiplier=1;
>
> Buycross= Cross(EMA1,EMA2);
> Counter=Cum(Buycross); //<== Here the crossover are counted with CUM
>
> // start loop
> for(i=0; i<BarCount;i++)
> {
> if (Counter[i]==threshold*multiplier)
> {
> multiplier++ AND exit[i]=1; // "AND"-statement?!?!
> }
> }
>
> printf("buycross:\n");
> WriteVal(Buycross,1);
> printf("counter:\n");
> WriteVal(Counter,1);
> printf("multiplier:\n");
> WriteVal(multiplier,1);
> printf("exit:\n");
> WriteVal(exit,1);
>
> Counter here is an array, as opposed to the 2nd example. Looks
strange, but works.
>
>
> Fine you might say, he did his job, so what's he asking for?
>
> I only achieved this by some means of trial and error and I don't
understand, why I have to add "AND" in the loop.So to say, I don't
understand what I did. Ok, check this:
>
> EMA1=EMA(C,10);
> EMA2=EMA(C,200);
> Plot(EMA1,"EMA10", colorRed,styleLine);
> Plot(EMA2,"EMA20",colorBlue,styleLine);
>
> Buycross[0]=0;
> exit[0]=0;
> COUNTER=0; //<==== Integer, variable
> threshold=3;
> multiplier=1;
>
> Buycross= Cross(EMA1,EMA2);
>
>
> // start loop
> for(i=0; i<BarCount;i++)
> {
> if (buycross[i]==0)
> {
> counter++; //<=== simple increment
> }
> if (Counter==threshold*multiplier)
> {
> multiplier++; //<=== The two statements without AND
> exit[i]=1; //<=== don't seem to work
> }
> }
>
> printf("buycross:\n");
> WriteVal(Buycross,1);
> printf("counter:\n");
> WriteVal(Counter,1);
> printf("multiplier:\n");
> WriteVal(multiplier,1);
> printf("exit:\n");
> WriteVal(exit,1);
>
> Eventhough my varible "counter" is initialized, the loop would simply
not do the increment. Like this, I cannot loop the process of crossover
counting. "counter" goes from 2 to 5, sometimes it's doing nothing or
even DEcreases. BTW, I'm checking every value of my OHLCV array from the
interpretation window.
> Also, the 2 statements would not be executed properly without the AND.
I finally accomplished my task in the first code but I do not understand
how AFL treats the variables / arrays in a loop. I believe I am not the
first one to experience this problem and I would appreciate any kind of
help or explanation. I just know that the 2nd code in C would rather
work.
>
> I considered varget, global varibale, but the problem didn't seem to
get resolved. What am I missing? Where should I look to read up on this?
>
>
> Thanks,
>
> Matthias
>
