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Thanks for the ideas. Let me explain what I am trying to grasp. I'll
show the sample given in the AB help file once again.
Ok, so in the function below there is a loop but before the loop I see
the two lines:
<<result[ 0 ] = input[ 0 ];>>
<<result[ 1 ] = input[ 1 ];>>
Now, in my mind this is creating an array. In VBA code you create
arrays by declaring a variable and assigning each element of the array
by using (0), (1), (2)... and so on. You then use this same method to
reference the individual elements in the array. So the way I read
these two lines is like this.
Assign Variable 'result' Element 1 = F-Argument 'input' Element 1
Assign Variable 'result' Element 2 = F-Argument 'input' Element 2
So far so good? This is where I'm confused. if you have input[0] and
input[1] available at the time of execution, then the argument 'input'
must be an array to begin with. Tell me if I'm wrong.
So, next is the loop:
<<for( i = 2; i < BarCount; i++ )>>
So I understand the 'i' is used to iterate through each element of the
array. At this point I have to assume 'input' is an array passed to
the function and the loop uses the first two elements of this array to
calculate and return a value. Here is where I am lost. Considering the
most likely candidate for 'input' would be the array of the closing
price of the stock, how can this thing work if it only uses the values
for the first two bars in the array [0] and [1]?
> function IIR2( input, f0, f1, f2 )
> {
> result[ 0 ] = input[ 0 ];
> result[ 1 ] = input[ 1 ];
>
> for( i = 2; i < BarCount; i++ )
> {
> result[ i ] = f0 * input[ i ] +
> f1 * result[ i - 1 ] +
> f2 * result[ i - 2 ];
> }
>
> return result;
> }
> //end code ***************************************
--- In amibroker@xxxxxxxxxxxxxxx, "Steve Dugas" <sjdugas@xxx> wrote:
>
> Hi again - just had another look at your question, I notice that you
just
> refer to "processing arrays". You picked an example that uses
looping but
> you can wrap any AFL in a function, you don't need to use looping
unless you
> really need it...Thnk of the function as sort of a container - it will
> basically hold any code that you could just as easily put inline,
not much
> reason to use one I don't think unless you want to call the code from
> several places or it is part of some larger organizational scheme...
>
> Steve
>
> ----- Original Message -----
> From: "Steve Dugas" <sjdugas@xxx>
> To: <amibroker@xxxxxxxxxxxxxxx>
> Sent: Saturday, August 09, 2008 7:18 PM
> Subject: Re: [amibroker] Using Functions to Process Arrays
>
>
> > Hi - Don't know of any tutorial but not sure you really need one.
Do you
> > understand basic looping already? You could start with any inline
looping
> > code. Once you have that working and understand it, you can just
wrap it
> > in
> > a function and pass it the arrays it needs via the function args.
Also,
> > make
> > sure the function is defined before it is called. I believe there
are a
> > couple of of looping tutorials in the files section, I wrote a
very brief
> > one and I think it was GP that wrote a better one. If you have
something
> > you
> > can't get to work, feel free to post it...
> >
> > Steve
> >
> > ----- Original Message -----
> > From: "Pete" <dryheat3@xxx>
> > To: <amibroker@xxxxxxxxxxxxxxx>
> > Sent: Saturday, August 09, 2008 6:37 PM
> > Subject: [amibroker] Using Functions to Process Arrays
> >
> >
> >>I have a bit of experience with building functions in VBA so I get the
> >> basic concept. But the projects I've built in the past did not rely
> >> heavily on processing arrays within functions. What I would really
> >> like is to get my brain around this so I understand exactly what's
> >> taking place and, hopefully, to better apply this technique to my AFL
> >> coding.
> >> From the AB help files:
> >> I simple function for a second order smoother:
> >> //begin code ************************************
> >> function IIR2( input, f0, f1, f2 )
> >> {
> >> result[ 0 ] = input[ 0 ];
> >> result[ 1 ] = input[ 1 ];
> >>
> >> for( i = 2; i < BarCount; i++ )
> >> {
> >> result[ i ] = f0 * input[ i ] +
> >> f1 * result[ i - 1 ] +
> >> f2 * result[ i - 2 ];
> >> }
> >>
> >> return result;
> >> }
> >> //end code ***************************************
> >>
> >> Do any of you know where I can get a quick and easy tutorial on
> >> processing arrays in functions so I can better understand how this
> >> looping works?
> >>
> >> Pete :-)
> >>
> >>
> >> ------------------------------------
> >>
> >> Please note that this group is for discussion between users only.
> >>
> >> To get support from AmiBroker please send an e-mail directly to
> >> SUPPORT {at} amibroker.com
> >>
> >> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
> >> http://www.amibroker.com/devlog/
> >>
> >> For other support material please check also:
> >> http://www.amibroker.com/support.html
> >> Yahoo! Groups Links
> >>
> >>
> >>
> >>
> >
> >
> >
> > ------------------------------------
> >
> > Please note that this group is for discussion between users only.
> >
> > To get support from AmiBroker please send an e-mail directly to
> > SUPPORT {at} amibroker.com
> >
> > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
> > http://www.amibroker.com/devlog/
> >
> > For other support material please check also:
> > http://www.amibroker.com/support.html
> > Yahoo! Groups Links
> >
> >
> >
> >
>
------------------------------------
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