Java Reference
In-Depth Information
</categorySeries>
</categoryDataset>
<bar3DPlot>
<plot />
</bar3DPlot>
</bar3DChart>
<!-- End 3D Bar Chart -->
</band>
</summary>
</jasperReport>
As we can see from the given example, the process used to create bar charts is very
similar to creating pie charts. This example creates two bar charts, a two-dimensional
one and a three-dimensional one. Let us discuss the two-dimensional one first.
The JRXML element used to create a two-dimensional bar chart is
<barchart>
. Just
like all charts in JasperReports, it must contain a
<chart>
sub-element, which contains
a
<reportElement>
sub-element defining the chart's dimensions and position.
The
<dataset>
element in a bar chart must be enclosed between
<categoryDataSet>
and
</categoryDataset>
JRXML elements.
<categoryDataSet>
must contain a
<categorySeries>
element. This element
defines what data element the bars will represent �aircraft models, in this example).
<categoryDataSet>
must also contain a
<categoryExpression>
element, which
defines how the data will be separated into categories for comparison. In the
previous example, data is separated by city. The
<valueExpression>
element
defines what expression to use to determine the value of each bar in the chart.
If we want to create 3-D bar charts, the JRXML element to use is
<bar3Dchart>
,
which works almost exactly the same way as
<barChart>
. The only difference is that
the
<plot/>
element must be a sub-element of
<bar3DPlot>
.
<bar3DPlot>
contains
three attributes,
isShowLabels
, which determines if labels will be shown in the
chart,
xOffset
, and
yOffset
, whose valid values are numeric values indicating the
number of pixels to use for the 3-D effect on the x and y axis, respectively.
XY Line Charts
XY line charts allow us to view the relationship between two numerical values. For
our next example, let us suppose we need to generate a report for a flight school
to illustrate how much the operating cost will be for flying a particular model of
their aircraft. Let us assume the flight school has an inventory of 43 of these aircraft,
and that the operating cost per day of each aircraft is $45. The JRXML template to
generate a report with a chart illustrating the operating cost would look like this:
