|
PureBytes Links
Trading Reference Links
|
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 in your table), how come it doesnt evaluate
to -1, like this? :
-1^10 = -(1^10) = -(1) =
-1
Steve
<BLOCKQUOTE
>
----- Original Message -----
<DIV
>From:
dtsokakis
To: <A title=amibroker@xxxxxxxxxx
href="">amibroker@xxxxxxxxxxxxxxx
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 numberAnother Amibroker expression is -1e10, also negative
enough.Your formula was not correct, because it was excuding stocks with
open==1 from counting.[see previous mails to you]DT**Operator
precedence and the parenthesesAFL 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 amibroker@xxxx, "Herman
van den Bergen" <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 isnot
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 amibroker@xxxx, "dtsokakis" <TSOKAKIS@xxxxx>
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 opinion is from experience, Tomasz knows how
AddToComposite()> > > works.> > > DT> >
> --- In 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 see from 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/>
>> >Your use of Yahoo! Groups is subject to
the Yahoo! Terms of
Service.
|