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Udo,
I know this table well :-)
But this table is for C++ language not for AFL.
AFL has much less operators.
1. There is no unary plus in AFL so we can not talk if unary
minus has a greater or lower precedence than plus in AFL :-)
2. There are no increment/decrement operators ++, --
in AFL
As I understand we were talking all the time about the AFL not
C.
Also I can not agree that unary plus and minus are assignment
operators. They have nothing to do with an assignment.
Best
regards,Tomasz Janeczkoamibroker.com
<BLOCKQUOTE
>
----- Original Message -----
<DIV
>From:
<A title=Udo.Harke@xxxx
href="">Udo.Harke@xxxx
To: <A title=amibroker@xxxxxxxxxx
href="">amibroker@xxxxxxxxxxxxxxx
Sent: Tuesday, April 30, 2002 8:42
PM
Subject: [amibroker] Unary Operators and
their Level of Precedence
Hi Tomasz,
Technically, increment and decrement
unary operators are assignment operators as well as
the unary minus (-) and unary plus (+)
operators:
In C++, the unary minusand
unary plus operators have a different level of precedence. The
same holds for the prefix and postfix form of the
increment/decrement operators.
Unfortunately, that understanding is
confused and misrepresented in many C/C++ books!
For your reference, you
may refer to Operator Precedence and Associativity in
MSDN Library Visual Studio 6.0 or, otherwise, please take a
look at the table below, which I obtained from that library.
<FONT face="Courier New"
size=2>
Regards,
Udo<FONT
face=Verdana size=2>
<A
name=_langref_operator_precedence_and_associativity><FONT
face=Arial color=#0000ff size=2>Operator Precedence and
Associativity
The table below lists the C and C++
operators and their precedence and associativity values. The highest
precedence level is at the top of the table.
<FONT face=Arial color=#0000ff
size=2>Symbol
<FONT face=Arial color=#0000ff
size=2>Name or Meaning
<FONT face=Arial color=#0000ff
size=2>Associativity
Highest
Precedence
<FONT face=Arial color=#0000ff
size=2>
++
<FONT face=Arial color=#0000ff
size=2>Post-increment
Left to
right
<FONT face=Arial color=#0000ff
size=2>--
<FONT face=Arial color=#0000ff
size=2>Post-decrement
<FONT face=Arial color=#0000ff
size=2>
( )
Function
call
<FONT face=Arial color=#0000ff
size=2>
[ ]
Array
element
<FONT face=Arial color=#0000ff
size=2>
<FONT
color=#0000ff>->
Pointerto
structure member
<FONT face=Arial color=#0000ff
size=2>
.
Structure or union
member
<FONT face=Arial color=#0000ff
size=2>
++
<FONT face=Arial color=#0000ff
size=2>Pre-increment
Right to
left
<FONT face=Arial color=#0000ff
size=2>--
<FONT face=Arial color=#0000ff
size=2>Pre-decrement
<FONT face=Arial color=#0000ff
size=2>
!
Logical
NOT
<FONT face=Arial color=#0000ff
size=2>
~
Bitwise
NOT
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>-
Unary
minus
<FONT face=Arial color=#0000ff
size=2>
+
Unary
plus
<FONT face=Arial color=#0000ff
size=2>
&
Address
<FONT face=Arial color=#0000ff
size=2>
*
<FONT face=Arial color=#0000ff
size=2>Indirection
<FONT face=Arial color=#0000ff
size=2>
sizeof
Size in
bytes
<FONT face=Arial color=#0000ff
size=2>
new
Allocate program
memory
<FONT face=Arial color=#0000ff
size=2>
delete
Deallocate program
memory
<FONT face=Arial color=#0000ff
size=2>
(type)
Type cast [for
example, (float) i]
<FONT face=Arial color=#0000ff
size=2>
<FONT
color=#0000ff>.*
Pointerto member
(objects)
Left to
right
<FONT
color=#0000ff>->*
Pointerto member
(pointers)
<FONT face=Arial color=#0000ff
size=2>
*
Multiply
Left to
right
/
Divide
<FONT face=Arial color=#0000ff
size=2>
%
<FONT face=Arial color=#0000ff
size=2>Remainder
<FONT face=Arial color=#0000ff
size=2>
+
Add
Left to
right
<FONT face=Arial color=#0000ff
size=2>-
Subtract
<FONT face=Arial color=#0000ff
size=2>
<<
Left
shift
Left to
right
>>
Right
shift
<FONT face=Arial color=#0000ff
size=2>
<
Less
than
Left to
right
<=
Less than or equal
to
<FONT face=Arial color=#0000ff
size=2>
>
Greater
than
<FONT face=Arial color=#0000ff
size=2>
>=
Greaterthan or
equal to
<FONT face=Arial color=#0000ff
size=2>
==
Equal
Left to
right
!=
Not
equal
<FONT face=Arial color=#0000ff
size=2>
&
Bitwise
AND
Left to
right
^
Bitwiseexclusive
OR
Left to
right
|
Bitwise
OR
Left to
right
<FONT face=Arial color=#0000ff
size=2>&&
Logical
AND
Left to
right
||
Logical
OR
Left to
right
?
:
<FONT face=Arial color=#0000ff
size=2>Conditional
Right to
left
=
<FONT face=Arial color=#0000ff
size=2>Assignment
Right to
left
*=, /=, %=, +=,
-=, <<=, >>=, &=, ^=, |=
Compound
assignment
<FONT face=Arial color=#0000ff
size=2>
,
Comma
Left to
right
Lowest
Precedence
<FONT face=Arial color=#0000ff
size=2>
<BLOCKQUOTE
>
-----Ursprüngliche Nachricht-----
<DIV
>Von:
Tomasz Janeczko
An: <A title=amibroker@xxxxxxxxxxxx
href="">amibroker@xxxxxxxxxxxxxxx
Gesendet: Dienstag, den 30. April 2002
16:53 Uhr
Betreff: Re: [amibroker] Re: Areyour
Composites accurate???
Richard,I just checked the parser code.You are
right unary minus has precedence over exponentiation.I think I should
change this behaviour to match documentation.Best regards,Tomasz
Janeczkoamibroker.com----- Original Message -----From: "Richard
Alford" <<A
href="">richard.alford@xxxx>To:
<<A
href="">amibroker@xxxxxxxxxxxxxxx>Sent:
Tuesday, April 30, 2002 3:27 PMSubject: Re: [amibroker] Re: Are your
Composites accurate???> Tomasz,>> I don't see
anything unusual or surprising in what you say. The only>
issue/question I have, and it is purely academic, is whether your>
documentation is, in fact, in minor error by showing exponentiation
as> higher precedence than the unary minus. Just for curiosity, can
you give an> example where exponentiation has higher precedence?I
have yet to see> anything in this thread that gives a surprising
result to me.>> Cheers,>> Richard> -----
Original Message -----> From: "Tomasz Janeczko" <<A
href="">amibroker@xxxx>> To: <<A
href="">amibroker@xxxxxxxxxxxxxxx>>
Sent: Tuesday, April 30, 2002 3:36 AM> Subject: Re: [amibroker] Re:
Are your Composites accurate???>>> >
Richard,> >> > The - (unary minus) operator negatesthe
value of the operand.> >> > The result of applying the
unary minus operator to a signed operand is> > equivalent to the
negative promoted type of the operand.> >> > For
example, if quality has the value 100, then -quality has the> value
-100.> >> > The unary minus has right associativityand
higher precedence than most> other> > operators
(except exponentiation)> > In the first Dimitris example the minus
sign is treated as> > binary minus (regular subtraction) there
fore the result is 10 - (3^2) => 10 - 9 = 1> > In the
second Dimitirs example the minus sign follows addition> >
operator. Addition (binary plus operator) expects numbers from left
and> right side.> > This time minus is treated as unary
minus operator> > So this is evaluated as:> >>
> 10 + ( (-3)^2 ) = 10 + 9 = 19> >> > (right
associativity of unary minus and precedence over binary plus>
operator).> >> > Best regards,> > Tomasz
Janeczko> > amibroker.com> > ----- Original Message
-----> > From: "dtsokakis" <<A
href="">TSOKAKIS@xxxx>> > To:
<<A
href="">amibroker@xxxxxxxxxxxxxxx>>
> Sent: Tuesday, April 30, 2002 9:07 AM> > Subject: [amibroker]
Re: Are your Composites accurate???> >> >> >
Richard,> > Note please that in AFL the following results are
true:> > 10-3^2=1> > 10+-3^2=19> > !!!>
> Dimitris Tsokakis> > --- In <A
href="">amibroker@xxxx..., "Richard Alford" <<A
href="">richard.alford@xxxx...> wrote:>
> > not in this universe :) It may not, in fact, matter since
the> > exponentiation operator always (by some other convention?)
follows> > the operand. Actually the "unitary" is a
relatively new term (in the> > past 20 years) jumping out after I
was well out of grad school (in> > mathematical physics) and
before the programmers began to worry about> > the difference
between subtraction and what I always interpreted as a> > simple
negative number - the computer worries about such things,> >
people don't. (I do realize the mathematical distinction has been>
> around for centuries - just ignored like most math in the real
world> > until it found a use.)> > >> >
> BTW - Multiplication and division are not generally on the same>
> level ( My Dear Aunt Sally) for the antiques in the group;
although,> > when in doubt most simply just hammer in parens by
reflex - similar> > to the way a horse runs first and asks
questions latter....> > >> > >> > > I
still think that this is a simple documentation error on TJ's> >
part , and,personally, I find that comforting :)> > >>
> > Cheers,> > >> > > Richard> >
> ----- Original Message -----> > >
From: Steve Dugas> > > To: <A
href="">amibroker@xxxx...> > >
Sent: Monday, April 29, 2002 8:34 PM> > > Subject:
Re: [amibroker] Re: Are your Composites accurate???> >
>> > >> > > It just occurred to me
- maybe they are on the same level (like> > multiplication and
division), so it does the negation first because> > it comes to it
first?> > >> > > Steve> >
> ----- Original Message -----> >
> From: Steve Dugas> >
> To: <A
href="">amibroker@xxxx...> >
> Sent: Monday, April 29, 2002 9:08 PM>
> > Subject: Re: [amibroker] Re: Are your
Composites accurate???> > >> > >> >
> Hi DT,> > >> >
> I must be missing something. I tried your plot,
and -1^10 did> > evaluate to 1, like you say. But, if
exponentiation takes precedence> > over negation (as shown inyour
table), how come it doesnt evaluate> > to -1, like this? :>
> >> > > -1^10 =
-(1^10) = -(1) = -1> > >> >
> Steve> >
> ----- Original Message
-----> > > From:
dtsokakis> > > To: <A
href="">amibroker@xxxx...> >
> Sent: Monday, April 29, 2002 12:16
PM> > > Subject:
[amibroker] Re: Are your Composites accurate???> > >>
> >> > >
Herman,> > > I really don´t
know how do you realise things.> >
> Well, -1^10 is equal to 1.>
> > [It acts like (-1)^10 because
of priorities in operators**> >
> [try Plot(-1^10,"",1,1);]>
> > -1*10^10 is a huge negative
number> > > Another
Amibroker expression is -1e10, also negative enough.> >
> Your formula was not correct,
because it was excuding stocks> > with> >
> open==1 from counting.[seeprevious
mails to you]> > >
DT> > > **Operator
precedence and the parentheses> >
> AFL supports parentheses in
formulas.> > >> >
> Parentheses can be used to control
the operation precedence> > (the> >
> order in which the operators are
calculated). AmiBroker> > always does> >
> operations within the innermost
parentheses first. When> > parentheses> >
> are not used, the precedence is as
follows (higher precedence> > listed> >
> first):> > >>
> > No Symbol Meaning>>
> 1 ^ Exponentiation> >
> 2 - Negation - Unary minus>
> > 3 * Multiplication>
> > 4 / Division> >
> 5 + Addition> >
> 6 - Subtraction> >
> 7 < Less than> >
> 8 > Greater than> >
> 9 <= Less than or equal
to> > > 10 >= Greater
than or equal to> > > 11 ==
Equal to> > > 12 != Not
equal to> > > 13 NOT
Logical "Not"> > > 14 AND
Logical "And"> > > 15 OR
Logical "Or"> > > 16 =
Variable assignment operator> > >> >
> The expression> >
>> > > H + L /
2;> > > (without
parenthesis) would be calculated by AmiBroker> > as "L /
2"> > > plus "H", since
division has a higher precedence. This would> > result>
> > in a much different value
than> > >> > >
(H + L)/2;> > >> >
> --- In <A
href="">amibroker@xxxx..., "Herman van den Bergen"<<A
href="">psytek@xxxx...>> > wrote:> >
> > > -----Original
Message-----> > > >>
From: dtsokakis [mailto:TSOKAKIS@xxxx]> >
> > > Sent: Sunday, April 28,
2002 11:13 AM> > > >
> To: amibroker@xxxx...> >
> > > Subject: [amibroker]Re:
Are your Composites accurate???> >
> > >> >
> > >> >
> > > Herman,> >
> > > I just noticed that your
EMPTY is -1^10, ie equal to 1.> >
> > > So, your equivalent
formula is> > > > >
EMPTY = 1;> > >
>> > > > Just
realized that -1^10 is not equal to 1 but is -1 * 10^10> >
> >> >
> > perhaps my code was OK
anyway?> > > >>
> > > Take care,> >
> > Herman.> >
> >> >
> >> >
> >> >
> >> >
> > > AddToComposite(IIf(Open
== 1,0,1),"~DataPresent","v",3);> >
> > > Do you have in the group
of your gif some stocks with> > open==1 ?> >
> > > This would give some
explanation.> > > >>
DT> > > > > PS The
huge negative symbol in AFL is -1e10> >
> > > --- In <A
href="">amibroker@xxxx..., "dtsokakis" <<A
href="">TSOKAKIS@xxxx...> wrote:> >
> > > > Of course I receive
an identical result list with your> >
> > > > EMPTY =
-1^10;> > > > > >
AddToComposite(IIf(Open ==> >
EMPTY,0,1),"~DataPresent","v",3);> >
> > > > Buy= 0;> >
> > > >
f=Foreign("~datapresent","v");> >
> > > >
Filter=f!=101;> > > >
> > AddColumn(f,"");> >
> > > > EXACTLY the same
results.> > > > >
> To avoid any misuderstanding :your formula works, I> > just
think> > > > > >
Amibroker does not use the open==EMPTY hypothesis,> > because
if> > > the> >
> > > > ADLAC is not present
on 16/4/2002, there is no> > reference for> >
> ADLAC> >
> > > > this date.>
> > > > > My opinionis
from experience, Tomasz knows how> > AddToComposite()>>
> > > > works.> >
> > > > DT> >
> > > > --- In <A
href="">amibroker@xxxx..., "Dimitris Tsokakis">
> <TSOKAKIS@xxxx...>> >
> wrote:> >
> > > > > I respectfully
disagree. If you are not concerned> > about bar-> >
> by-> >
> > > bar> >
> > > > accuracy>
> > > > > > than you
are correct. In that case the "1" method> > works fine.>
> > As> >
> > > > long as you>
> > > > > > know that
this method will pick up holes of several> > days but>>
> that> >
> > > > it will>>
> > > > > not pick up
single bar holes.> > > >
> > >> > > >
> > >> > > >
> > > Herman,> > >
> > > > Of course we speak for daily search, bar-by-bar.>
> > > > > > I have in
my ^NDX 4 experimental holes on> >
> > > > > 6/1/2000 [1],
15/2/2000 [1] and 1/3/2000[2]> >
> > > > > plus the
missing ADLAC after 15/4/2002.> >
> > > > > As you seefrom
the exploration, the population> >
> > > > > is different
from 101 exactly these dates.> >
> > > > > I do not
understand the conditions of your graph.> >
> > > > > The>
> > > > > >
AddToComposite(1,"~count","v");> >
> > > > > Buy=0;>
> > > > > > scans
bar-by-bar every stock for each date.> >
> > > > > If the stock is
present, it adds an 1 and moves to> > the next> >
> stock.> >
> > > > > If ADLAC is not
present on 16/4/2002, then the sum> > will be 100> >
> > > > > for the certain
date.> > > > > >
> It is impossible to have a 20% error, there should be> >
another> > > > >>
> reason for your results.> >
> > > > > Dimitris
Tsokakis> > > >
>> > > > >>
> > > >> >
> > >> >
> > >> >
> > > Your use of Yahoo! Groups
is subject to> > > <A
href="">http://docs.yahoo.com/info/terms/>
> > > >> >
> > >> > >>
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Service.> > >> > >> > >> >
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