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Yes. I'm a computer illiterate. There is no doubt about that :)
And you are beautiful and always right :)))
And yes! I wrote my message loop in AFL... I enjoyed it! 15 years old
memories flashed back :)
Still, AB is not even close to what is called event driven programming
modell.
I didn't even mention lack of step through debugging, and lack of
error/exception handling. :(
I did not intend to hurt you. AB is still a great tool. But handling
multiple order status changes in AFL is not for newcomers...
Regards,
Y
--------------------------------------------------
From: "Tomasz Janeczko" <groups@xxxxxxxxxxxxx>
Sent: Monday, March 09, 2009 9:38 PM
To: <amibroker@xxxxxxxxxxxxxxx>
Subject: Re: [amibroker] Re: Events in AB/AFL - use of
www.Amibroker.com/feedback
> Sorry, but clearly your knowledge about computers is very limited.
>
> In Windows OS, all programs execute strictly sequentially. And all this
> "event driven" processing in Windows is actually single big loop
> that calls non-stop GetMessage function and that processes the
> message through sequence of conditional statements (either
> switch, message crackers, if-else or whatever)
>
> http://www.winprog.org/tutorial/message_loop.html
>
> Thus, in Windows, the whole "event driven" programming is nothing
> more than just a big switch that calls appropriate functions.
>
> Frameworks that implement those "event driven" programming do just
> that - get the message, then go through big switch/if-else to
> determine the message and call appropriate function (i.e. "event
> handler").
>
> And exactly the same method can be used in AFL.
>
> Nothing stops you from writing all your event handlers are simple
> functions and call them depending on what event caused AFL execution.
>
> Exact copy-paste solution is actually included in the User's Manual,
> see:
> http://www.amibroker.com/guide/afl/afl_view.php?id=297
>
> So, read the fine manual first.
>
> Best regards,
> Tomasz Janeczko
> amibroker.com
> ----- Original Message -----
> From: "Yofa" <jtoth100@xxxxxxxxxxx>
> To: <amibroker@xxxxxxxxxxxxxxx>
> Sent: Monday, March 09, 2009 8:42 PM
> Subject: Re: [amibroker] Re: Events in AB/AFL - use of
> www.Amibroker.com/feedback
>
>
>> Hi All,
>>
>> to clarify what event driven programming model means read this article
>> http://en.wikipedia.org/wiki/Event-driven_programming
>>
>> To make it short and simple: the whole AFL code executes as a "single
>> batch"
>> when some event (new tick, time refresh etc.) occures in AB. And then AFL
>> code has to "search for" the event caused the execution.
>> In an event driven modell event handler code segments are executed when
>> specific events occure. Usually the programming environment "looks for"
>> events and knows what code fragment (event handler) to execute.
>>
>> AFL programming model and the language is not really best suite for this.
>> You can overcome this by writing your own "message loop" in AFL.
>> May not be elegent and reliable enough and it is a lot of pain as there
>> is
>> no real debugging support but it works if you use not to small
>> timeframes.
>> If you want to do high frequency trading look around for other platforms.
>> Use AB what it is really good for: develop trading strategies.
>>
>> Regards,
>>
>> Y
>>
>> Ps: There is a lot of code out there... Noone wants to rewrite them. AFL
>> is
>> efficient language to process arrays.
>> But putting an event driven, broker/exchange interface integrated
>> "execution" module that can access the AFL and charting engines sounds a
>> much better idea.
>>
>> --------------------------------------------------
>> From: "Dennis Brown" <see3d@xxxxxxxxxxx>
>> Sent: Monday, March 09, 2009 5:19 PM
>> To: <amibroker@xxxxxxxxxxxxxxx>
>> Subject: Re: [amibroker] Re: Events in AB/AFL - use of
>> www.Amibroker.com/feedback
>>
>>> Gordon,
>>>
>>> AFL is event driven. Some event causes your AFL program to execute.
>>> You can check to see which event caused it to run and run all or a
>>> portion of your program depending on the event.
>>>
>>> Check back on your suggestion again for an example of bar closed.
>>>
>>> You can suggest a new event type that is not already covered if you
>>> need one. However, because the AFL engine is shared between all
>>> charts, a particular chart's AFL will have to wait until a currently
>>> executing chart is done before the next one can be executed. So the
>>> AFL engine looks for the next chart that has an event only when it is
>>> idle.
>>>
>>> One event that has been suggested before, that would be useful to me
>>> as well, is an AFL self programmed event. This would be some AFL
>>> statement that would cause the currently running chart to be put into
>>> the queue to be run again as soon as possible --subject to some CPU
>>> loading constraints, or after a specified delay less than a second.
>>> Currently, if no quotes are coming in, one second is the fastest
>>> guaranteed repeat AFL execution. I have some sequences related to
>>> changing parameters that require 4 passes of the AFL to trigger
>>> certain conditions that have to happen between AFL passes. I shut
>>> down all but the essential AFL during these sequential passes, but
>>> time drags on when you have to wait for one second each pass.
>>>
>>> Best regards,
>>> Dennis
>>>
>>> On Mar 9, 2009, at 11:50 AM, Gordon wrote:
>>>
>>>> Hi sidhartha70,
>>>>
>>>> Thanks for your thoughts. I actually did try something like that,
>>>> but seemed to find some sensitive timing issues. My objective was,
>>>> as soon as I detected a new bar (this was using one minute bars), to
>>>> access information about the just completed bar. At least in my
>>>> experience, it was necessary to introduce a delay so that the
>>>> Ref(XYZ, -1) function returned information about the bar I was
>>>> interested in and not the one before it. In the end, I just felt
>>>> uncomfortable that I had an approach I could rely on as being rock
>>>> solid.
>>>>
>>>> I think I'll revisit it, but in the end, would love to be able to
>>>> rely on a built-in function. Assuming I'm successful in revisting a
>>>> one-off solution, I'll post the results (code).
>>>>
>>>> The exploration start/stop is a little tougher. One way to do it is
>>>> to invoke AA through VBScript, and do your own pre- and post-
>>>> processing. Another might be to create ficticious symbols guaranteed
>>>> to be the first and last symbols visited by the exploration code and
>>>> use the name() function to test for them.
>>>>
>>>> Regards,
>>>>
>>>> Gordon
>>>>
>>>> --- In amibroker@xxxxxxxxxxxxxxx, "sidhartha70" <sidhartha70@xxx>
>>>> wrote:
>>>>>
>>>>> Gordon,
>>>>>
>>>>> I'm pretty sure you can code for this type of stuff already in AFL.
>>>>> You can simply set up your on checks to see if an event has
>>>>> occurred, and if it has, execute any code you want...
>>>>>
>>>>> For example, OnBar() that you are talking about could be achieved
>>>>> by looking for a change in DateTime() of the most recent bar...
>>>>>
>>>>> --- In amibroker@xxxxxxxxxxxxxxx, "Gordon" <gordon@> wrote:
>>>>>>
>>>>>> Hi All,
>>>>>>
>>>>>> I just posted a new suggestion at www.Amibroker.com/feedback. It
>>>>>> occurred to me that most AB users don't know about or use the
>>>>>> feedback area. So, I wanted to take a second to highlight the
>>>>>> value of using the site to add suggestions and provide feedback
>>>>>> for existing ones. If you haven't gone there (you need to be a
>>>>>> registered AB user), there are tons of neat suggestions.
>>>>>>
>>>>>> My second reason for posting is, I'm curious to know how many
>>>>>> would find the addition event-based AFL coding useful -- e.g.
>>>>>> functions you write that would be executed automatically upon the
>>>>>> occurrence of specific events, such as the current bar jused
>>>>>> completed (geared toward tick and other intra-day charts),
>>>>>> backtester started, exploration finished, etc.
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> Gordon
>>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------------
>>>>
>>>> **** IMPORTANT PLEASE READ ****
>>>> This group is for the discussion between users only.
>>>> This is *NOT* technical support channel.
>>>>
>>>> TO GET TECHNICAL SUPPORT send an e-mail directly to
>>>> SUPPORT {at} amibroker.com
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>>>> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
>>>> http://www.amibroker.com/feedback/
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>>>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
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>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> ------------------------------------
>>>
>>> **** IMPORTANT PLEASE READ ****
>>> This group is for the discussion between users only.
>>> This is *NOT* technical support channel.
>>>
>>> TO GET TECHNICAL SUPPORT send an e-mail directly to
>>> SUPPORT {at} amibroker.com
>>>
>>> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
>>> http://www.amibroker.com/feedback/
>>> (submissions sent via other channels won't be considered)
>>>
>>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
>>> http://www.amibroker.com/devlog/
>>>
>>> Yahoo! Groups Links
>>>
>>>
>>>
>>>
>>
>>
>> ------------------------------------
>>
>> **** IMPORTANT PLEASE READ ****
>> This group is for the discussion between users only.
>> This is *NOT* technical support channel.
>>
>> TO GET TECHNICAL SUPPORT send an e-mail directly to
>> SUPPORT {at} amibroker.com
>>
>> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
>> http://www.amibroker.com/feedback/
>> (submissions sent via other channels won't be considered)
>>
>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
>> http://www.amibroker.com/devlog/
>>
>> Yahoo! Groups Links
>>
>>
>>
>
>
> ------------------------------------
>
> **** IMPORTANT PLEASE READ ****
> This group is for the discussion between users only.
> This is *NOT* technical support channel.
>
> TO GET TECHNICAL SUPPORT send an e-mail directly to
> SUPPORT {at} amibroker.com
>
> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
> http://www.amibroker.com/feedback/
> (submissions sent via other channels won't be considered)
>
> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
> http://www.amibroker.com/devlog/
>
> Yahoo! Groups Links
>
>
>
>
------------------------------------
**** IMPORTANT PLEASE READ ****
This group is for the discussion between users only.
This is *NOT* technical support channel.
TO GET TECHNICAL SUPPORT send an e-mail directly to
SUPPORT {at} amibroker.com
TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
http://www.amibroker.com/feedback/
(submissions sent via other channels won't be considered)
For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
http://www.amibroker.com/devlog/
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