|
PureBytes Links
Trading Reference Links
|
why would you want to change the value of a variable, give them
different names and save the headaches
On 11/3/05, vlanschot <ecbu@xxxxxxxxxxxxxx> wrote:
> Don't know whether this is helpful in clarifying it, but I'll give it
> a try:
>
> Say I have an AFL which looks like this:
>
> bla bla bla . . . . .
>
> examplevar=C/2; // This examplevar is now defined and thus already by
> definition a global variable !
>
> bla bla bla . . . .
>
> function Trial()
> {
> global examplevar; // Here I define examplevar again, but now as a
> global variable within the function; this will cause a problem as
> we'll see
>
> . . . .
> anotherexamplevar=H/2;
>
> examplevar=C/3;
>
> return anotherexamplevar;
> }
>
> . . . .
>
> CallTrial = Trial();
>
> CallExampleVar=examplevar;// This returns the value of the very first
> definition of examplevar, thus the one before = outside the function.
> It is therefore NOT equal to the "examplevar" defined as a global
> variable within the function. In fact, there is no way to catch this
> latter value, unless you change the code/names/etc.
>
> This is my understanding and how I use it.
>
> PS
>
>
>
> --- In amibroker@xxxxxxxxxxxxxxx, "Ara Kaloustian" <ara1@xxxx> wrote:
> >
> > Exactly ... That's how I use it ... but it is not working reliably
> >
> > Ara
> > ----- Original Message -----
> > From: "Graham" <kavemanperth@xxxx>
> > To: <amibroker@xxxxxxxxxxxxxxx>
> > Sent: Wednesday, November 02, 2005 6:26 PM
> > Subject: Re: [amibroker] Re: Global variables
> >
> >
> > > If I want to use a variable that is defined within a function or
> > > procedure I first define it as a globla variable within the
> function
> > > or procedure. it is then available within the AFL after that
> function
> > > or procedure has been called
> > >
> > > On 11/3/05, Chuck <cstangor232@xxxx> wrote:
> > > > According to the help manual, this is how global and local
> variables
> > relate
> > > > to functions (depends on where they are first defined):
> > > >
> > > > If given identifier appears first INSIDE function definition -
> then it
> > is
> > > > treated as LOCAL variable.
> > > > If given identifier appears first OUTSIDE function definition -
> then it
> > is
> > > > treated as GLOBAL variable.
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: "Ara Kaloustian" <ara1@xxxx>
> > > > To: <amibroker@xxxxxxxxxxxxxxx>
> > > > Sent: Wednesday, November 02, 2005 12:12 PM
> > > > Subject: Re: [amibroker] Re: Global variables
> > > >
> > > >
> > > > > Barry
> > > > >
> > > > > this is getting confusing ...
> > > > >
> > > > > Globals defined as such within a function seem available
> globally ...
> > but
> > > > > as
> > > > > I indicated earlier... not reliably.
> > > > >
> > > > > According to the help files, there is no distinction between
> globals
> > > > > defined
> > > > > within functions and variables initialized outside of
> functions.
> > > > >
> > > > > Where did you see the distinction you mentioned?
> > > > >
> > > > > Hope this thread resolves the "mystery" of globals.
> > > > >
> > > > >
> > > > > Ara
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "Barry Scarborough" <razzbarry@xxxx>
> > > > > To: <amibroker@xxxxxxxxxxxxxxx>
> > > > > Sent: Wednesday, November 02, 2005 8:54 AM
> > > > > Subject: [amibroker] Re: Global variables
> > > > >
> > > > >
> > > > >> Global variables defined withing a function are scoped to
> that
> > > > >> function and all the sub functions within that function. But
> once
> > > > >> you call outside that function the variable is not
> available. If you
> > > > >> want the variable to be global it has to be in a global
> scope,
> > > > >> outside of the functions that will use it. Declare it at the
> top of
> > > > >> your code and it will have global scope as you mentioned.
> Otherwise
> > > > >> pass it as a parameter. This is much safer. You have to be
> careful
> > > > >> when using globals because anyone can change a global
> anytime and
> > > > >> anywhere, darn hard to debug if that happens. If that is OK
> then
> > > > >> make it global.
> > > > >>
> > > > >> I would have to look at your code to see what you are doing.
> > > > >>
> > > > >> Barry
> > > > >>
> > > > >> --- In amibroker@xxxxxxxxxxxxxxx, "Ara Kaloustian"
> <ara1@xxxx>
> > > > >> wrote:
> > > > >> >
> > > > >> > I have had some problems with defining globals within a
> function.
> > > > >> >
> > > > >> > Globals defined withing a function are not always
> available to
> > > > >> code later on. In one situation, a global defined within a
> prior
> > > > >> function and used in an indicator, was not available to some
> copies
> > > > >> of the indicator and was available to some others where the
> > > > >> indicator was used multiple times in same instance, but on
> different
> > > > >> panes.
> > > > >> >
> > > > >> > If I initialize the variable at the beginning of the
> program, it
> > > > >> is automatically a global and always works reliably.
> > > > >> >
> > > > >> > Anyone with similar issues?
> > > > >> >
> > > > >> > Ara
> > > > >> >
> > > > >>
> > > > >>
> > > > >>
> > > > >>
> > > > >>
> > > > >>
> > > > >>
> > > > >> 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 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 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 other support material please check also:
> > > > http://www.amibroker.com/support.html
> > > >
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > > --
> > > Cheers
> > > Graham
> > > AB-Write >< Professional AFL Writing Service
> > > Yes, I write AFL code to your requirements
> > > http://e-wire.net.au/~eb_kavan/ab_write.htm
> > >
> > >
> > >
> > > 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 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 other support material please check also:
> http://www.amibroker.com/support.html
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
--
Cheers
Graham
AB-Write >< Professional AFL Writing Service
Yes, I write AFL code to your requirements
http://e-wire.net.au/~eb_kavan/ab_write.htm
------------------------ Yahoo! Groups Sponsor --------------------~-->
Try Online Currency Trading with GFT. Free 50K Demo. Trade
24 Hours. Commission-Free.
http://us.click.yahoo.com/RvFikB/9M2KAA/U1CZAA/GHeqlB/TM
--------------------------------------------------------------------~->
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 other support material please check also:
http://www.amibroker.com/support.html
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/amibroker/
<*> To unsubscribe from this group, send an email to:
amibroker-unsubscribe@xxxxxxxxxxxxxxx
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|