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Thanks Tomasz.
I sent you an e-mail.
--- In amibroker@xxxxxxxxxxxxxxx, "Tomasz Janeczko" <groups@xxx> wrote:
>
> There is no special "penalty" for using looping, however same
> code written using array operators will always be faster.
> Literally almost every code can be written using array operators,
> with some thinking. As always - post ENTIRE formula if you want help.
> Also look at SetBarsRequired function to limit the number of bars
> that are used.
>
> Best regards,
> Tomasz Janeczko
> amibroker.com
> ----- Original Message -----
> From: "sidhartha70" <sidhartha70@xxx>
> To: <amibroker@xxxxxxxxxxxxxxx>
> Sent: Thursday, May 22, 2008 11:24 PM
> Subject: [amibroker] Re: General query about cumulating values for
indicators
>
>
> > Tomasz,
> >
> > I have already read the link you provided. Sadly one needs to make
> > mistakes sometimes to completely understand.
> > Sorry, I should have rephrased my statement. You cannot change the
> > value of an array by recursively referencing earlier values with the
> > following syntax (which those of us coming from other languages are
> > used to),
> >
> > Value1=Ref(Value1,-1) * 2;
> >
> > for example. But that's fine. I now understand that this cannot be
> > done, and I have implemented the looping structures I posted in my
> > previous message.
> >
> > I am however, now finding this indicator pretty slow at intraday level
> > when scrolling through charts. Is there a large speed penalty to using
> > the looping structures as I have....?
> >
> > Many Thanks
> >
> >
> > --- In amibroker@xxxxxxxxxxxxxxx, "Tomasz Janeczko" <groups@> wrote:
> >>
> >> No, you are making assumptions instead of reading the manual.
> >> AFL does NOT work on bar-by-bar basis. It works on WHOLE ARRAYS,
> >> unless you tell it NOT to do so by using a loop.
> >>
> >> User's Guide: Understanding AFL:
> >> http://www.amibroker.com/guide/h_understandafl.html
> >>
> >> (THIS IS MUST READ FOR EVERYONE)
> >> ===============================
> >>
> >> Best regards,
> >> Tomasz Janeczko
> >> amibroker.com
> >> ----- Original Message -----
> >> From: "sidhartha70" <sidhartha70@>
> >> To: <amibroker@xxxxxxxxxxxxxxx>
> >> Sent: Thursday, May 22, 2008 10:56 PM
> >> Subject: [amibroker] Re: General query about cumulating values for
> > indicators
> >>
> >>
> >> > Mike,
> >> >
> >> > you seem to know your onions... While I'm here can I ask you
another
> >> > question...
> >> >
> >> > Can you clear up for me exactly 'how' AFL executes it's code...
> >> >
> >> > When I say 'how', this is what I mean. Coming from C# world, it's
> >> > pretty clear that trading type software tends to work on a bar
by bar
> >> > basis... i.e. you have an event driven call, of the like,
> >> > OnNewBar()... in that event call you place the code that you want
> >> > executed on each bar...
> >> >
> >> > It's not clear to me 'how' AFL is called. If I'm applying an
> >> > indicator, how many times is that indicator code called...??
> >> >
> >> > The reason I ask is, generally the way AFL works with arrays seems
> >> > very efficient... until perhaps you start having to loop through
> >> > arrays as part of your code... for example,
> >> >
> >> > for(i=1;i<BarCount;i++)
> >> > {
> >> >
> >
Value9[i]=IIf(Value7[i]!=Value8[i],((Value6[i]-Value8[i])/(Value7[i]-Value8[i])-0.5)+0.5*Value9[i-1],Value9[i]);
> >> > Value9[i]=IIf(Value9[i]>0.9999,0.9999,Value9[i]);
> >> > Value9[i]=IIf(Value9[i]<-0.9999,-0.9999,Value9[i]);
> >> >
> >
Value10[i]=IIf(Value9[i]!=1,0.25*log((1+Value9[i])/(1-Value9[i]))+0.5*Value10[i-1],Value10[i]);
> >> > }
> >> >
> >> > I have recently added this code to one of my indicators and it does
> >> > seem very slow when scrolling through graphs. Perhaps my code is
> >> > inefficient...??
> >> >
> >> > I'm running a beast of a machine here, so speed should not be an
> > issue.
> >> >
> >> > If I can understand 'how' AFL excutes... it might help me
understand
> >> > bottlenecks.
> >> >
> >> > Many Thanks
> >> >
> >> >
> >> >
> >> > --- In amibroker@xxxxxxxxxxxxxxx, "Mike" <sfclimbers@> wrote:
> >> >>
> >> >> Nope, you're not alone.
> >> >>
> >> >> The topic pops up, in one form or another, every couple of
weeks or
> >> >> so. Sounds like you understand the concept now.
> >> >>
> >> >> Good luck.
> >> >>
> >> >> Mike
> >> >>
> >> >> --- In amibroker@xxxxxxxxxxxxxxx, "sidhartha70" <sidhartha70@>
> >> >> wrote:
> >> >> >
> >> >> > Thanks Mike.
> >> >> >
> >> >> > So it seems I'm not the only one coming from more 'traditional'
> >> >> > languages to struggle with this concept.
> >> >> >
> >> >> > The bottom line it seems is that you cannot recursively
alter the
> >> >> > value of any array by referencing other values of that
array... at
> >> >> > least not directly.
> >> >> >
> >> >> >
> >> >> > --- In amibroker@xxxxxxxxxxxxxxx, "Mike" <sfclimbers@> wrote:
> >> >> > >
> >> >> > > Read thread #122034 for a similar discussion, including
> >> >> explanation.
> >> >> > >
> >> >> > > Mike
> >> >> > >
> >> >> > > --- In amibroker@xxxxxxxxxxxxxxx, "sidhartha70"
<sidhartha70@>
> >> >> > > wrote:
> >> >> > > >
> >> >> > > > Hi All,
> >> >> > > >
> >> >> > > > Can someone clear this up for me... I am simply trying to
> >> >> cumulate
> >> >> > > the
> >> >> > > > value of an array. My intial thoughts were to do something
> > like
> >> >> the
> >> >> > > > following,
> >> >> > > >
> >> >> > > > Value1=0;
> >> >> > > > Value2=log(Close);
> >> >> > > > Value1=Ref(Value1,-1)+Value2;
> >> >> > > >
> >> >> > > > However, that doesn't seem to work... So I've ended up with,
> >> >> > > >
> >> >> > > > Value2=log(Close);
> >> >> > > > Value1=Cum(Value2);
> >> >> > > >
> >> >> > > > Which does seem to work. I can't see why the first doesn't.
> >> >> > > >
> >> >> > > > Can anyone explain...? Thanks
> >> >> > > >
> >> >> > >
> >> >> >
> >> >>
> >> >
> >> >
> >> >
> >> > ------------------------------------
> >> >
> >> > 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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