Specifying axis properties
Graphs have two or three axes. You specify the axes’ properties
in the Axis page in the graph’s Properties view.
To specify properties for an axis of a graph
-
Select Properties from the graph’s pop-up menu and then
select the Axis page in the Properties view. -
Select the Category, the Value, or the Series axis from the
Axis drop-down list.If you are not working with a 3D graph, the Series Axis
options are disabled. -
Specify the properties as described next.
Specifying text
properties
You can specify the characteristics of the text that displays
for each axis. The following table shows the two kinds of text
associated with an axis.
|
Type of text |
Meaning |
|---|---|
|
Text |
Text that identifies the values for an |
|
Label |
Text that describes the axis. You specify the |
For information on specifying properties for the text, see Specifying text properties for titles, labels, axes,
and legends.
Specifying datatypes
The data graphed along the Value, Category, and Series axes has
an assigned datatype. The Series axis always has the datatype String.
The Value and Category axes can have the datatypes listed in the
following table.
|
Axis |
Possible datatypes |
|---|---|
|
Both axes (for scatter graph) |
Number, Date, Time |
|
Value (other graph types) |
Number, Date, DateTime, Time |
|
Category (other graph types) |
String, Number, Date, DateTime, |
For graphs in DataWindow objects, PowerBuilder automatically
assigns the datatypes based on the datatype of the corresponding
column; you do not specify them.
For graphs in windows, you specify the datatypes yourself. Be
sure you specify the appropriate datatypes so that when you populate
the graph (using the AddData method), the data matches the
datatype.
Scaling axes
You can specify the properties listed in the following table to
define the scaling used along numeric axes.
|
Property |
Meaning |
|---|---|
|
Autoscale |
If selected (the default), PowerBuilder |
|
RoundTo, RoundToUnit |
Specifies how to round the end points of the axis You can |
|
MinimumValue, MaximumValue |
The smallest and largest numbers to appear on the |
|
ScaleType |
Specifies linear or logarithmic scaling (common |
|
ScaleValue |
Specifies whether values are displayed as actual |
Using major and minor
divisions
You can divide axes into divisions. Each division is identified
by a tick mark, which is a short line that intersects an axis. In the
Sales by Printer graphs shown in Examples, the graph’s Value axis is divided
into major divisions of 50 units each. PowerBuilder divides the axes
automatically into major divisions.
To define divisions for an axis of a graph
-
To divide an axis into a specific number of major divisions,
type the number of divisions you want in the MajorDivisions
box. -
Leave the number 0 to have PowerBuilder automatically create
divisions. PowerBuilder labels each tick mark in major divisions.
If you do not want each tick mark labeled, enter a value in the
DisplayEveryNLabels box. For example, if you enter 2, PowerBuilder
labels every second tick mark for the major divisions. -
To use minor divisions, which are divisions within each
major division, type the appropriate number in the MinorDivisions
box. To use no minor divisions, leave the number 0.When using logarithmic axes
If you want minor divisions, specify 1; otherwise, specify
0.
Representing divisions with grid and drop
lines
You can specify lines to represent the divisions as described in
the following table and illustrated in the following figure.
|
Line |
Meaning |
|---|---|
|
Grid line |
A line that extends from a tick mark across the |
|
Drop line |
A line that extends vertically from a data point |
Using line styles
You can define line styles for the components of a graph listed
in The following table.
|
Component |
Meaning |
|---|---|
|
PrimaryLine |
The axis itself |
|
SecondaryLine |
The axis parallel to and opposite the primary |
|
OriginLine |
A grid line that represents the value |
|
Frame |
The frame for the axis in 3D graphs (disabled for |