May I have my attributes discretized based on my own expression?

Hi, all here.

I am just having one question about discretization of continous attributes values. Cos the current discretization methods available in SQL Server 2005 data mining engine are these 3 ones:

.......................................................................................

automatic;

equal areas;

clusters.

..........................................................................................

So how these 3 methods work respectively? I mean like clusters method, how dose it discretize the continous values?

More importantly, can we have a discretization based on our own expression? like when i have one column with values ranging from 1 to 10, may we discretize this column based on expression like: 1-3,4-6,7-10?

Thanks a lot for any guidance.

User-defined ranges are not supported.

Here are descriptions of the supported discretization methods:

· Clusters: This finds buckets by performing single-dimensional clustering on the input values using the K-Means algorithm. It uses Gaussian distributions.

· EqualAreas: This examines the distribution of values across the population and creates bucket ranges such that that the total population is distributed equally across the buckets. In other words, if the distribution of continuous values were plotted as a curve, the areas under the curve covered by each bucket range would be equal. This is useful when there are a large number of duplicate values.

· Automatic: If this is selected, we try obtaining the requested number of buckets by applying the above discretization methods in the following order: Clusters, EqualAreas. We use the first method that gets closest to the number of requested buckets.

The Clusters method use random sampling (with a sample size of 1000) so EqualAreas may be used in situations where sampling is not desirable.

|||Hi, Thanks a lot.|||

However, you can always add a calculated column to do your own discretization. For example you can add a column "AgeDisc" with the expression

CASE WHEN [Age]<20 THEN 'Under 20'
WHEN [Age] <= 30 THEN 'Between 20 and 30'
ELSE 'Over 30'
END

Of course, you will have to map any input data to these values for predictions.

|||Jamie, thanks a lot. Very helpful.

Maximum Memory and SQL 2005 (Yukon)

I beleive Express has a memory limit of 1GB, but does anyone know what the
Standard Edition memory limit will be when its released? ie Current Std Ed
is 2GB.
Thanks
Mickb
>I beleive Express has a memory limit of 1GB, but does anyone know what the
> Standard Edition memory limit will be when its released? ie Current Std Ed
> is 2GB.
I don't believe that this information has been decided, and if it has, I
don't think it is public yet.
A

Maximum Memory and SQL 2005 (Yukon)

I beleive Express has a memory limit of 1GB, but does anyone know what the
Standard Edition memory limit will be when its released? ie Current Std Ed
is 2GB.
Thanks
Mickb>I beleive Express has a memory limit of 1GB, but does anyone know what the
> Standard Edition memory limit will be when its released? ie Current Std Ed
> is 2GB.
I don't believe that this information has been decided, and if it has, I
don't think it is public yet.
A

Maximum Memory and SQL 2005 (Yukon)

I beleive Express has a memory limit of 1GB, but does anyone know what the
Standard Edition memory limit will be when its released? ie Current Std Ed
is 2GB.
Thanks
Mickb>I beleive Express has a memory limit of 1GB, but does anyone know what the
> Standard Edition memory limit will be when its released? ie Current Std Ed
> is 2GB.
I don't believe that this information has been decided, and if it has, I
don't think it is public yet.
A

Maximum Attribute Values

I have a procedure that detarmines the maximum current values of user table
attributes. However I don't know how to use SQL to get the maximum value of
a
datatype. Can anyone help?There's no way to get them via SQL AFAIK, but you can just look them up in
Books Online, under the specific datatypes.
Jacco Schalkwijk
SQL Server MVP
"marcmc" <marcmc@.discussions.microsoft.com> wrote in message
news:247D52AD-2959-493F-9DC5-E38E6F031EF7@.microsoft.com...
>I have a procedure that detarmines the maximum current values of user table
> attributes. However I don't know how to use SQL to get the maximum value
> of a
> datatype. Can anyone help?|||To add to Jacco's response, you can also get the min/max permissible values
for numeric types in .Net application code using constants in the
System.Data.SqlTypes namespace (e.g. SqlInt32.MaxValue).
Hope this helps.
Dan Guzman
SQL Server MVP
"marcmc" <marcmc@.discussions.microsoft.com> wrote in message
news:247D52AD-2959-493F-9DC5-E38E6F031EF7@.microsoft.com...
>I have a procedure that detarmines the maximum current values of user table
> attributes. However I don't know how to use SQL to get the maximum value
> of a
> datatype. Can anyone help?|||try looking at the system table systypes
regards,
Mark Baekdal
http://www.dbghost.com
http://www.innovartis.co.uk
+44 (0)208 241 1762
Build, Comparison and Synchronization from Source Control = Database change
management for SQL Server
"marcmc" wrote:

> I have a procedure that detarmines the maximum current values of user tabl
e
> attributes. However I don't know how to use SQL to get the maximum value o
f a
> datatype. Can anyone help?|||Thx
So you can't get them in SQL? How then does it know ehen they are exceeded?
"Dan Guzman" wrote:

> To add to Jacco's response, you can also get the min/max permissible value
s
> for numeric types in .Net application code using constants in the
> System.Data.SqlTypes namespace (e.g. SqlInt32.MaxValue).
> --
> Hope this helps.
> Dan Guzman
> SQL Server MVP
> "marcmc" <marcmc@.discussions.microsoft.com> wrote in message
> news:247D52AD-2959-493F-9DC5-E38E6F031EF7@.microsoft.com...
>
>|||> So you can't get them in SQL? How then does it know ehen they are
exceeded?
because the engine is not written in tsql.|||I know that it's not recommended to query system tables directly, but isn't
the information accessible through the systypes table.
INT is listed with a length of 4 but you can easily calculate the max and
min values from this.
The problem that I see would be that Microsoft modifies this table in the
future.
"Jacco Schalkwijk" <jacco.please.reply@.to.newsgroups.mvps.org.invalid> wrote
in message news:ustFpMBQFHA.3544@.TK2MSFTNGP12.phx.gbl...
> There's no way to get them via SQL AFAIK, but you can just look them up in
> Books Online, under the specific datatypes.
> --
> Jacco Schalkwijk
> SQL Server MVP
>
> "marcmc" <marcmc@.discussions.microsoft.com> wrote in message
> news:247D52AD-2959-493F-9DC5-E38E6F031EF7@.microsoft.com...
>|||Because an overflow exception is thrown by the engine.
----
Louis Davidson - drsql@.hotmail.com
SQL Server MVP
Compass Technology Management - www.compass.net
Pro SQL Server 2000 Database Design -
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"marcmc" <marcmc@.discussions.microsoft.com> wrote in message
news:E68737B1-89BA-4915-A1F0-EF816A91DF05@.microsoft.com...
> Thx
> So you can't get them in SQL? How then does it know ehen they are
> exceeded?
>
> "Dan Guzman" wrote:
>|||I know of no way to get this info in Transact-SQL. The characteristics of
built-in datatypes are hard-coded in the engine code so these don't need to
be stored as meta-data or exposed.
Hope this helps.
Dan Guzman
SQL Server MVP
"marcmc" <marcmc@.discussions.microsoft.com> wrote in message
news:E68737B1-89BA-4915-A1F0-EF816A91DF05@.microsoft.com...
> Thx
> So you can't get them in SQL? How then does it know ehen they are
> exceeded?
>
> "Dan Guzman" wrote:
>|||Keep in mind that underneath SQL's engine is a simple check that detemrines
whether the numeric data it is trying to store is larger than the byte thres
hold
(Integer=4, SmallInt=2, TinyInt=1). It's not "storing" the maximum decimal v
alue
per se. You just have to know that the range of an integer is 2^31 to 2^31-1
.
Thomas
"marcmc" <marcmc@.discussions.microsoft.com> wrote in message
news:E68737B1-89BA-4915-A1F0-EF816A91DF05@.microsoft.com...
> Thx
> So you can't get them in SQL? How then does it know ehen they are exceeded
?
>
> "Dan Guzman" wrote:
>

Max with Datepart

I am wanting to set any given @.Date parameter to the most current recorded Monday in a table (tblMarketPricing). Would this work:

@.Date = Max(Datepart(dw,MktDate) IN 2

I am unsure if you can use Max with the Datepart function.

***If this is not allowed, can anyone suggest anything different that I might try?

To get what you are asking for you need:

Select @.date = Max(MktDate) from tblMarketPricing where DatePart(dw, MktDate) = 2

assuming that 2 corresponds to Monday on your system.

You could consider using the DateName() function in place of DatePart().

Since it will otherwise be forthcoming, I will suggest that a Calendar table could also be used to provide these sorts of answers.

|||That worked! Thank you.