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Tomasz,
I was wrong. You are not "absolutely" right saying: "in ANY language
you should not use a variable without initializing it first."
Not in ANY language. I forgot about scripting languages like
JavaScript :)
Mike
--- In amibroker@xxxx, "mik954" <mik-u@xxxx> wrote:
> Tomasz,
>
> Sorry to bother you with this stupid question. You are absolutly
> right that "in ANY language you should not use a variable without
> initializing it first." But in AFL we deal with not scalar
variables,
> but ARRAYS. So when I want to initialize array, in fact I want to
> initialize a "pointer" to array, not ALL ACTUAL VALUES of array.
> Right?
>
> Here is my idea in English:
>
> Buy signal will be accepted only if previous ACTUAL trade in the
same
> direction was a loss.
>
> Here is the code which doesn't work:
>
> Buy = 0;
> Sell = 0;
> tradeProfit = 0;
>
> Buy = longEntry and ValueWhen(Sell, tradeProfit) < 0);
> Sell = LongExit;
> tradeProfit = ValueWhen(Sell, SellPrice) - ValueWhen(Buy,
BuyPrice);
>
> The problem is that ValueWhen(Sell, tradeProfit) always returns 0.
> May be because "initialization" of tradeProfit resets all previous
> values to 0.
>
> I guest something like this might work:
>
> var Sell;
> var tradeProfit;
>
> Buy = longEntry and ValueWhen(Sell, tradeProfit) < 0);
> Sell = LongExit;
> tradeProfit = ValueWhen(Sell, SellPrice) - ValueWhen(Buy,
BuyPrice);
>
>
> Thanks,
> Mike
>
>
>
> --- In amibroker@xxxx, "Tomasz Janeczko" <amibroker@xxxx> wrote:
> > Mike,
> >
> > In fact in ANY language you should not use a variable without
> initializing it first.
> > But as to the problem - it would be better if you explain in
plain
> english
> > what do you want to achieve, then it will be possible to write
the
> code.
> >
> > Best regards,
> > Tomasz Janeczko
> > amibroker.com
> > ----- Original Message -----
> > From: "mik954" <mik-u@xxxx>
> > To: <amibroker@xxxx>
> > Sent: Tuesday, April 23, 2002 3:50 PM
> > Subject: [amibroker] Re: Declare variable for future use:
> Left/Right side of the formula
> >
> >
> > > Tomasz,
> > >
> > > Thank you for the links describing AFL arrays.
> > >
> > > But I still don't know how I can benefit from AMA/AMA2
functions
> to
> > > fix my problem.
> > >
> > > The problem is how to obtain a value from an array using
ValueWhen
> ()
> > > function (on the right side of the formula) before
> setting/defining
> > > this array on the left side of the formala.
> > >
> > > In Excel I don't need to declare any rows/columns: they are all
> > > predefined. Therefore I can use any new row/column on the left
> and
> > > right side of the formula at any time.
> > >
> > > As I understand in AFL I CANNOT use an array on the right side
of
> the
> > > formula before using it on the left side.. That's my PROBLEM.
> > >
> > > A simle fix would be using some kind of declaration (var for
> example,
> > > like in VB/JS Script) to allow using of array on the right side
> of
> > > the formula.
> > >
> > > Thanks,
> > > Mike
> > >
> > >
> > >
> > >
> > >
> > > --- In amibroker@xxxx, "Tomasz Janeczko" <amibroker@xxxx> wrote:
> > > > Mike,
> > > >
> > > > There are numerous possibilities to reference previous value
of
> the
> > > indicator or any array.
> > > > Please check out
http://www.amibroker.net/boards/viewtopic.php?
> t=81
> > > for the details.
> > > >
> > > > Best regards,
> > > > Tomasz Janeczko
> > > > amibroker.com
> > > > ----- Original Message -----
> > > > From: "mik954" <mik-u@xxxx>
> > > > To: <amibroker@xxxx>
> > > > Sent: Tuesday, April 23, 2002 2:15 AM
> > > > Subject: [amibroker] Re: Declare variable for future use: No
> way in
> > > AFL?
> > > >
> > > >
> > > > > Tomasz,
> > > > >
> > > > > You mean that I cannot use REF() function to get a previous
> > > element
> > > > > of an ARRAY mentioned later in the code?
> > > > >
> > > > > So in AFL there is no way to use a previous value of a
> variable
> > > to
> > > > > define its new value? What a disappointment. Is there any
> > > workaround?
> > > > >
> > > > > Thanks,
> > > > > Mike
> > > > >
> > > > >
> > > > > --- In amibroker@xxxx, "Tomasz Janeczko" <amibroker@xxxx>
> wrote:
> > > > > > Mike,
> > > > > >
> > > > > > No, AFL operates on entire arrays and it uses only single-
> pass
> > > to
> > > > > process all bars.
> > > > > > So if you assign a value later in your code it will have
no
> > > effect
> > > > > on any lines that appeared
> > > > > > before.
> > > > > >
> > > > > > Best regards,
> > > > > > Tomasz Janeczko
> > > > > > amibroker.com
> > > > > > ----- Original Message -----
> > > > > > From: "mik954" <mik-u@xxxx>
> > > > > > To: <amibroker@xxxx>
> > > > > > Sent: Monday, April 22, 2002 6:13 PM
> > > > > > Subject: [amibroker] Declare variable for future use (was
> TJ:
> > > > > Actual trade profit vs. Theoretical)
> > > > > >
> > > > > >
> > > > > > > Hi, all!
> > > > > > >
> > > > > > > Well, so far no any response on my initial post (even
on
> > > direct e-
> > > > > > > mail to support@xxxx). It's weird. Maybe my question
> wasn't
> > > > > > > clear, or Tomasz was too busy.
> > > > > > >
> > > > > > > OK, let me ask in a different way. Is there any way in
> AFL to
> > > > > declare
> > > > > > > variable/array and use its previos value before setting
> > > current
> > > > > one?
> > > > > > >
> > > > > > > I mean:
> > > > > > >
> > > > > > > // var tradeProfit; // declare variable for future use
> > > > > > >
> > > > > > > Buy = longEntry and ValueWhen(Sell, tradeProfit) < 0;
> > > > > > > Sell = LongExit;
> > > > > > >
> > > > > > > tradeProfit = ValueWhen(Sell, SellPrice) - ValueWhen
(Buy,
> > > > > BuyPrice);
> > > > > > >
> > > > > > >
> > > > > > > Any suggestions are welcome.
> > > > > > >
> > > > > > > Thanks,
> > > > > > > Mike
> > > > > > >
> > > > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Your use of Yahoo! Groups is subject to
> > > http://docs.yahoo.com/info/terms/
> > > > >
> > > > >
> > > > >
> > >
> > >
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
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