----- Original Message -----
Sent: Sunday, August 14,
2005 5:46 PM
Subject: RE: [amibroker]
Ticker Symbol Length Issues
Tomasz,
I was afraid that it would be a big
issue.
Regarding using the Full Name, I like the
idea and it IS technically feasible in my code, BUT…
Using the Full Name is NOT logistically
feasible (AFAIK). The key problem (in this case, it’s a “Big
Problem”) is the combination of:
1. The need to map one symbol to another through the Full Name, and
2. The inability to programmatically set the Full Name for a symbol.
I.e., according to the documentation, the
Full Name would have to be entered manually.
Currently, even at the immature state of
my system development, I’ve created 807 composite symbols.
Over the next several weeks when I test ideas, I expect this number to grow by
a factor of 3 to 5 – 2,000 to 4,000 thousand symbols.
Manually entering the Full Name for
thousands of symbols is simply not feasible.
How can the Full Name be programmatically
entered during a scan when the Composite symbol is created?
Regards,
Dan.
From: amibroker@xxxxxxxxxxxxxxx [mailto:amibroker@xxxxxxxxxxxxxxx] On Behalf Of Tomasz Janeczko
Sent: Sunday, August 14, 2005 1:35
AM
To: amibroker@xxxxxxxxxxxxxxx
Subject: Re: [amibroker] Ticker
Symbol Length Issues
Symbol length is 25 characters and won't be changed now
because it would mean change of core symbol record,
which would mean that databases between versions are not
compatible, so you would not be able to use database
created with say version 4.80 in version 4.70 or earlier.
Not to mention amount of work required plus the fact
that will break some of existing plugins.
Instead, I suggest usign numerical encoding of industries:
it will take just 3 digits
And use full name field to store "human-readable"
description of composite you are creating - so you will be able
to see it in the tooltip.
Full name is 64 characters.
Best regards,
Tomasz Janeczko
amibroker.com
----- Original Message -----
Sent: Sunday, August 14,
2005 8:11 AM
Subject: [amibroker] Ticker
Symbol Length Issues
Hi,
I’ve discovered the joys of Composite symbols.
However…
I ran into what appears to be a serious issue when creating
Composite symbols – ticker symbol length. It appears that the
maximum length for a ticker symbol is 25 characters.
When creating Composite symbols, you append or prepend a
character string to differentiate types of Composite symbols. If the
first 25 characters of a Composite symbol are exactly the same, the excess
characters are truncated and values are merged to one symbol. The symbol
is then corrupt.
For example, I create QP Industry Composite indexes of my
stock list, and then create an “Indicator” Composite symbol of each
Industry Index symbol. Here’s how the error occurs:
·
QP has two Industries:
Aerospace-Defense
Aerospace-Defense Eqp
·
Composite Industry indexes are created by prepending
“~iInd_” to the industry name:
~iInd_Aerospace-Defense
~iInd_Aerospace-Defense E
Notice that “qp” is
truncated from the second industry.
·
Then Composite Indicator symbols are created by prepending
“Rk” to the Industry Index symbols:
“Rk~iInd_Aerospace-Defense”
However, instead of two Composite
Indicator symbols, only ONE is created! Since the left 25 characters of
the Indicator Composite symbol (“Rk” + Industry Index symbol name)
are same for both Industries, values from the two Industry Index symbols are
merged to one Indicator Symbol!
Composite Indexes and Indicator symbols are a HUGE
benefit. Composite Indicator symbols allow me to preprocess and save
Indicators like RSI, and then use them like a normal ticker.
Before, my scans and charts computed Sector and Industry Rank on the fly, which
was SLOW! Now, with Sector and Industry Composite Rank symbols, scans and
charts are at least 3 times faster!
How can I get around this character length limitation?
Tweaking symbol names might work for a while, but at some point the
symbol names will become meaningless. Can I increase the Symbol
length? Tomasz, can you increase Symbol length?
Thanks and regards,
Dan.