On the Specify class
and ID variables page, you can specify the columns from the source
table that are to be included in the target aggregation table as class
variables and as ID variables. After the class and ID variables have
been selected, you can modify the name, label, and the format attributes
of the output columns. These changes can be performed on the Specify
column details page of the wizard for summarized aggregations.
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A class variable is used to group
or classify data. For example, the value of a class variable could
be a device address.
At least one variable
must be selected as a class variable.
Note: If aging is being performed
on this target aggregation table, then the aging column is automatically
added to the list of class columns. The aging column cannot be deleted
from the list of class variables if it is in use as the aging column.
If aging is turned off, the column can be removed from the list of
class variables.
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An identification (ID) variable
contains an alternate identifier for the data in a class variable.
For example, the value of the corresponding ID variable could be the
name of a particular device.
ID variables are not
required.
To select class columns
for the target aggregation, perform the following steps:
-
Highlight the columns
in the
Available variables panel that you
want to select as class columns.
-
Click the right arrow
to move those columns into the
Selected class variables.
To select ID columns
for the target table, perform the following steps:
-
Highlight the columns
in the
Available variables panel that you
want to select as ID columns.
-
Click the right arrow
to move those columns into the
Selected ID variables.
Note: If a variable is based on
a time period that is greater than your aging column, do not specify
it as a class column. Instead, specify it as an ID column. For example,
if your aging column is DAYDATE, do not specify WEEKDATE as another
class column. Instead specify it as an ID column.
You can select the
entire list of available columns by clicking the double right arrow.
Back arrows can be used to deselect one, several, or all columns.
After your data has
been aggregated, you can change the class list. If you remove columns
from the class list, the existing data in the summarized aggregation
table is merged again so that it matches the new class list. If you
add new columns to the class list, then these new columns in the summarized
aggregation table will have a missing value (for numeric) or blank
value (for character) in the existing data. (You cannot remove a class
or ID column if it is used as the source for a join column in another
aggregation table. Similarly, you cannot remove a class or ID column
if it is used as the source column of a rank column in this aggregation
table.)
The value that is assigned
to the ID variable is the last value that is read into the group that
is defined by the unique combination of class variables.
Note: If an input column is given
a role as a class variable, ID variable, or a statistic, it cannot
simultaneously be assigned a different role. Therefore, it will not
be available for selection. If all available variables are assigned
as class or ID variables, then no variables will be available to be
used as analysis variables. In that case, the Select analysis variables
page will not be displayed. Similarly, if no analysis variables are
selected, the Specify statistics page will not be displayed.