A polar graph is a circular scatter graph. In a polar graph, as in a scatter graph, data is represented by the location of data markers. In a polar graph, the plot area, where the markers appear, is circular.
You use polar graphs to show correlations between:
Two different measures
Two dimension values in the same measure
Like scatter graphs, polar graphs are especially useful when you have a number of data items and you want to see the general relationships. Use polar graphs rather than scatter graphs when the data might have a directional aspect.
Only one variety of polar graph is available. The constant is POLAR
.
The DepthRadius
and DepthAngle
properties of the
Graph
object together specify whether a polar graph appears to
have depth.
The following figure shows the data structure of a polar graph. This graph is populated with the Promotional Expense and Sales measures (in that order).
The data structure for polar graphs is as follows:
A group is a two-column set or, if data columns are shown as series, then a two-row set. It is represented by all markers that belong to the same dimension member, such as all markers for January. Groups are hard to identify in a polar graph, but it is not as important to identify groups. You are generally looking more for the overall pattern of the data markres. Groups are labeled by marker text, which is not visible by default.
A series is represented by all the markers of the same color and is labeled by legend text, such as Patient A.
Each data marker in a polar graph represents two column values:
The first measure value is the X value. It determines the location of the marker along the X-axis, which is the location around the graph.
The second measure value is the Y value. It determines the location of the marker along the Y-axis, which is the distance from the center of the graph.
Polar graph data has the following guidelines:
Graphs display numeric data only.
Polar graphs require at least two columns of data. If you pass only one column of data, then the Graph bean displays a message about insufficient data, instead of displaying a graph.
The following polar graph is populated with the Promotional Expense and Sales measures, in that order. For simplicity in this example, each series of data has only one marker in it. Normally, polar graphs have a number of markers.
The following crosstab shows the same data as the graph. Notice that there are two columns
of data for each marker in the graph. This picture assumes that
isDataRowShownAsASeries
returns true
.
Handling Problems
in Graph Data
Specifying Data for a Graph
Example: Setting JDBC Data on
a Scatter Graph
Example: Setting Data from a
File on a Scatter Graph