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Folks,
Would it be possible to have a routine which would
delete unwanted indices from the input file so that the database is not loaded
with unwanted material in the first place.
I'd like to be able to cull the daily fileto
remove all tickers of length greater than 3 whic the exception of the major
indices which I'd like to keep.
Does anyone have a solution please ?
Thanks,
Geoff
<BLOCKQUOTE
>
----- Original Message -----
<DIV
>From:
David
Holzgrefe
To: <A
href=""
title=amibroker@xxxxxxxxxxx>amibroker@xxxxxxxxxxx
Sent: Thursday, November 30, 2000 4:34
PM
Subject: Re: [amibroker] Culling
database
Thanks Donald,I will have a look at what you
recommendations, may I point out that I usecharting programs tohelp
me trade, I have very little time to learnprogramming skills
Amibroker would have to be one of the most comprehensivecharting programs
I have seen most of it is easy to use with a littlepractice, as a trader
the main thing I want to do is scan my charts for keypoint (indicators)
and trademain things I want form a program are:1. easy to build
indicator searches2. the ability to save data quickly into watch lists for
further scanning orwatching over a period.3. keep track of my trade
portfolio all trades open and closed (tax reasons)hmm that had better
do for now I seem to have got off the topic----- Original Message
-----From: "Donald Dalley" <ddalley@xxxx>To: "Peter B.
White" <amibroker@xxxx>Sent: Thursday, November 30, 20009:01
AMSubject: Re: [amibroker] Culling database>> Hello,
David & Peter:>> On 29-Nov-00, Peter B. White
wrote:>> > Further to David's question about cleaning upthe
database.> > Is it possible to create a routine which will select
stocks which havenot> > been quoted for a week? If that list
could be created then it would be a> > simple matter to delete them
using the Delete function.>> I have written to the list about
this in the past, but it won't hurt to go> over it again. Maybe this
needs to be made into an FAQ. Having built anumber> of databases of
complete exchanges, over the years, I still manually cull> non-trading
stocks.>> Why?>> Some reasons that I use follow.
Some may apply to how you updatedatabases.> Other people may have
just as valid reasons to do this automatically, butit's> not my
style, since I use a method of adding *any & all* tickers found
inthe> data that I collect for my main databases. Therefore,
deleting anycurrently> valid ticker would be pointless. My REBOL US
data collecting programsdepend> on the database itself being
up-to-date - that keeps it simple.>> In Canada (most countries
now have one or more stock exchanges), we havethree> main
exchanges, plus a brand new NASDAQ Canada exchange. Some juniorstocks
on> junior exchanges grow up to be the big stocks, and I don't want to
losethese> histories of possibly interesting & profitable
companies. With a large> database, knowing when major changes occur to
each and every ticker isnearly> impossible. If a company movesfrom
a junior exchange to the senior TSE, I> would not want to automatically
lose the history from the juniorexchange's>
database.>> Even some fairly large US companies, such as Gateway
(GATE @ NASD, now GTW@> NYSE), move between
exchanges.>> Also, not all stocks (micro-caps, prefereds,
different classes, warrants &> rights, etc.) of a complete exchange
will trade daily. Some trade onlyonce or> twice a year. The
Australian ASX has other worries.>> If a take-over/merger makes
a ticker redundant because it changed (JDSinto> JDU), you may not
want to lose the supporting data in an otherwise currentAB>
file.>> An automatic culling program would delete these still
important files. Ifyou> make a mistake, you need to rebuild a file.
While not usually a big deal> (depending upon the country, the data may
be irreplacable!), it stilltakes> time).>>>
Now, even if you don't follow a whole exchange, here are some
suggestionsto> make manual deletion more efficient. Some involve
*no* programming, just> common sense & good
organisation.>> - decide more strictly, in the first place,
whether you actually want toadd a> new stockinto
your main database> - set up a database for new stocks, then move those
you actually keep> up-to-date into your permanent
database> - don't delete them (if the company interested you in the
past, it mightbe> best to just keep the file-
use filters to ignore low-interesttickers)> - use a script to make
a list of all "last trades" or not recently traded>
stocks, with tickers (and other useful info, if you
wish...)> - refer to a hard copy for deletions,
especially if you have manytickers> - an ARexx
program, "names.rexx", at my web site may help with
theprogram>
logic> - this idea has many useful applications,so
it is a good one to learn> - use a script to sequentially select any
stock that hasn't traded inn-days,> then,
optionally, manually do a delete (this should be pretty
efficient> with small databases)> - set up a
group for new tickers and use a script to delete all
remainingin> that group** (be careful that the
group really is up-to-date, first)> - look with your file manager at
the file dates of the database files,> then delete
out-of-date stocks> - do this only with AmiBroker
*not* running> - ONLY do this if you know your
tickers *very, very* well> - alternatively, don't
delete the files, move them to a temp
drawer,> then delete them later (if
you change your mind, you don't need
to> rebuild the file, just up-date
it)>> I am sure there are more ways of doing this, but this
should be enough toget> you thinking about some very differentways
to get the job done. Justthink> >very seriously< as to
whether you really want to do it
automatically,though.>>> One subject that I still
have to work on is automatically deleting any> supporting files, such
as a profile, for a stock that we need toeliminate.>> ** I
still think it would be a good idea to be able to display only those>
stocks in a group, sector, industry or market.>> Please letme
know if this helps anyone out there.>>
-->>
---===///||| Donald Dalley
|||\\\===--->
The World of AmiBroker
Support>
<A
href="">http://webhome.idirect.com/~ddalley>
UIN/ICQ#: 65203020>>>>>
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