Databases Reference
In-Depth Information
5.
Select the
Airline
,
Origin Country
, and
Destination Country
fields from
the list of
Available Fields
and click on
Add >
move them under the
Used
Fields
list.
6.
Click on
OK
to close the
Group Settings
dialog window.
7.
Click on
OK
to close the
Document Properties
window.
We have now created a cyclic group called
Airline_Origin_Destination
that we can
use as a dimension in our charts.
When creating a cyclic group, make sure to select the
Cyclic
Group
radio button from the
Group Settings
dialog window. By
default this radio button is set to the
Drill-down Group
value.
A few interesting things to take note of:
• In the
Group Settings
dialog, the
Label
input box can be used to override the
display label of the field.
• Besides fields from the data model, an expression can also be used to define
a field. This field can be added using the
Add Expression
button and will
behave as a calculated dimension.
• In our example, we opened the
Group Settings
dialog via the
Document
Properties
window. It can also be opened via the
Edit Groups…
button,
which can be found on the
Dimensions
tab of chart objects. This method
is probably more convenient, as it fits better into the workflow of creating
a new chart object; it is the one we previously discussed in
Chapter 2
,
Seeing
is Believing
.
A drill-down group is created in the same way as a cyclic group, the only difference
is that the fields in the
Used Fields
list are not cycled through, but represent the
various levels in a drill-down hierarchy. The top field is the highest aggregation,
while the lowest field has the most detail. Our
Traffic per Year
chart uses a drill-
down group based on time; its defined hierarchy consists only of two fields:
Year
and
Month
.
It is advisable to ensure that only fields that have a "proper" hierarchy are used for
drill-down groups.
