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Thanks Tomasz,
I have been speculating about that stuff for a while now so it is a
relief to get presented with the facts and have it all cleared up.
BrianB.
--- In amibroker@xxxxxxxxxxxxxxx, "Tomasz Janeczko" <groups@xxx>
wrote:
>
> Hello,
>
> The reason why fundamental data implemented in AB are current only
are as follows:
>
> a)
> Yahoo nor any other free source of fundamental data does not
provide historical values
> for majority of fields. The idea behind new fundamental data
functionality in AB
> was to couple it with a method to actually RETRIEVE this data
automatically.
> Since only current values are available from Yahoo, so there was
no point in bumping
> database size for functionality that would be left unused for most
people
>
> b)
> The idea was to help scanning (stock picks) based on fundamentals
only.
>
> Backtesting systems based on fundamentals requires 20+ years of
data to make any sense
> (because they change so infrequently - otherwise you would have
too small data sample to make results resonable).
>
> Since AB target user base is not really that long-term investors,
and there are no
> free data (see a)) it made even less sense
>
> c)
> The idea was to add functionality without growing database - AB
database format was prepared
> for fundamentals since day 1 (May 1995) but there were no method
to access these fields.
>
>
> As to SQL advantages: using external database
> a) you have unlimited number of custom fields of any type
> b) you can store less frequent data effectively (if you have
quarterly data using external database
> you would store just 4 records per year)
> c) you can access these data from external ODBC-aware programs
>
> Overall the general idea of AmiBroker is as follows:
> a) core functionality is provided internally + means to easy
update from FREE sources
> b) extra functionality is provided by means of plugins / external
sources / scripts
>
> This design ensures that
> a) AmiBroker is not bloated with stuff that almost no one is using
> b) AmiBroker delivers flexibility allowing individuals to extend
its functionality. And here you are limited only by your
> imagination.
>
> Best regards,
> Tomasz Janeczko
> amibroker.com
> ----- Original Message -----
> From: "treliff" <treliff@xxx>
> To: <amibroker@xxxxxxxxxxxxxxx>
> Sent: Sunday, July 23, 2006 9:41 AM
> Subject: [amibroker] Re: On Fundamental data import
>
>
> > Being a long-time artificial ticker-er myself (and an absolute
non-
> > programmer) I think one disadvantage of this method is that,
assuming
> > a daily data base, we are creating arrays with many, many
duplicate
> > values. For example an array containing EPS (in one of the OHLCVI
> > fields) would only change about 4 times a year; during 3
consecutive
> > months we are stuffing this array with the same value.
> >
> > I can imagine this simply puts a lot of strain on the AB
database.
> > And for example 30 fundamentals divided among 5 arti-tickers for
each
> > stock increases a 2,000 stock database to 10,000 "stocks".
> >
> > I am just assuming this because if not, then why would TJ not
have
> > implemented the new fundamentals as arrays, in this case not
with 6
> > OHLCVI datafields but with one single datafield, so indeed daily
(or
> > bulk ASCII) imported (funda) values would build a historical
database
> > completely within AB similar to price data.
> >
> > I remember though having read requests for "custom arrays" in
deep
> > historical depths of the message board archives, so there must
be a
> > good reason why these were never implemented.
> >
> > But just as dbirru I'd be very interested to know if SQL will
have a
> > serious advantage over artificial tickers. I am absolutely
ignorant
> > about SQL so will this be worth digging into?
> >
> > Thanks very much for advice from TJ or other experts.
> >
> > -treliff
> >
> > --- In amibroker@xxxxxxxxxxxxxxx, "Michael.S.G." <OzFalconAB@>
> > wrote:
> >>
> >> If you import your fundamental data into artificial tickers (eg
> >> Code-FndData) to create a historical database of Fnd Data,
> >> Then it appears as though these new additions have little
benefit
> > to us.
> >> I do the same thing, And reference with Foreign.
> >>
> >> I find it quite convenient to access historical fundamental
data
> >> "within" amibroker, As opposed to accessing some external DB.
> >> I mean, AmiBroker itself is a DB. So why make things more
> > complicated
> >> by accessing external db's. (Just my thoughts).
> >> Im not sure it would be any quicker using external database as
> > opposed
> >> to AB inbuilt Foreign function.
> >>
> >> The only gripe I have, And I dare say it would be the same if
the
> > data
> >> was stored in an external DB - Is the inability of the
> >> shiftx or ref() functions to access Future Foreign data (As in
> > reference
> >> to the Selected ticker).
> >>
> >> Here is example of charting historical fundamental data accesed
via
> > an
> >> artificial (foriegn) ticker.
> >>
> >>
> >> dbirru wrote:
> >> >
> >> > Is the new fundamental import faster compared to doing it via
the
> > old
> >> > way of the ascii importer?
> >> >
> >> > I used to import fundamental data using artifical ticker and
the
> > ascii
> >> > importer (using the 9 or so available fields). In AFL, this
> > requires
> >> > using the foreign function. I find that this method slows down
> >> > exploration considerably since for every ticker a
corresponding
> >> > ticker need to be read. The values are also stored in an
array.
> >> >
> >> > The latest ascii importer contains additional fields to ease
> > improting
> >> > of fundamental data. Does this new way of improting
fundamental
> > data
> >> > make exploration considerably faster? If the dat astructure is
> >> > different, then I expect it may be faster. But, I don't know
the
> > data
> >> > structure. Thus, I asked before I try it and 'corrupt' my
> > database if
> >> > it does not offer an advantage.
> >> >
> >> > 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 other support material please check also:
> > http://www.amibroker.com/support.html
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> >
>
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