Users Guide
About graphs

Area, bar, column, and line graphs are conceptually very similar. They differ only in how they physically represent the data values—whether they use areas, bars, columns, or lines to represent the values. All other properties are the same. Typically you use area and line graphs to display continuous data and use bar and column graphs to display noncontinuous data.

The only difference between a bar graph and a column graph is the orientation: in column graphs, values are plotted along the y axis and categories are plotted along the x axis. In bar graphs, values are plotted along the x axis and categories are plotted along the y axis.

Pie graphs typically show one series of data points with each data point shown as a percentage of a whole. The following pie graph shows the sales for Stellar printers for each quarter. You can easily see the relative values in each quarter. (PowerBuilder automatically calculates the percentages of each slice of the pie.)

You can have pie graphs with more than one series if you want; the series are shown in concentric circles. Multiseries pie graphs can be useful in comparing series of data.

Scatter graphs show xy data points. Typically you use scatter graphs to show the relationship between two sets of numeric values.Non-numeric values, such as string and DateTime datatypes, do not display correctly.

Scatter graphs do not use categories. Instead, numeric values are plotted along both axes—as opposed to other graphs, which have values along one axis and categories along the other axis.

For example, the following data shows the effect of speed on the mileage of a sedan:

Here is the data in a scatter graph:

You can have multiple series of data in a scatter graph. You might want to plot mileage versus speed for several makes of cars in the same graph.

Traditional 3D graphs

You can also create 3-dimensional (3D) graphs of area, bar, column, line, and pie graphs. In 3D graphs (except for 3D pie graphs), series are plotted along a third axis (the Series axis) instead of along the Category axis. You can specify the perspective to use to show the third dimension:

DirectX 3D graphs

DirectX 3D rendering allows you to display the 3D graphs (Pie3D, Bar3D, Column3D, Line3D, and Area3D) with a more sophisticated look. You can use data item or series transparency with the DirectX graph styles to improve the presentation of data.

The DirectX graph rendering style is supported for standalone graph controls and for graph controls in a DataWindow object. PowerBuilder uses the following functions to support the DirectX graph styles:

DirectX runtime. The DirectX 3D rendering depends on the DirectX runtime. The first time you select the Render3D check box on the General tab of the Properties view for a 3D graph, PowerBuilder launches the DirectX installer. If you opt out of the installation, the Render3D property is ignored. End users of PowerBuilder applications must also have the DirectX runtime installed on their computers.

If you install DirectX on the runtime computer, but selecting the Render3D check box does not change the appearance of the graph, it is possible that the graphics card does not support DirectX.

You can check whether DirectX is supported by running dxdiag.exe. This file is typically installed in the Windows\System32 directory. The Display tab of the DirectX Diagnostic Tool that opens when you run dxdiag.exe indicates whether Direct3D is enabled.

In bar and column graphs, you can choose to stack the bars and columns. In stacked graphs, each category is represented as one bar or column instead of as separate bars or columns for each series: