JMSL Chart Programmer's Guide

3D Drawing Elements >> AxisXYZ

AxisXYZ

The AxisXYZ node is the basis of both the scatter chart types and surface chart. Its parent node must be the root Chart3D node.

When an AxisXYZ node is created, it creates three Axis3D nodes. They can be obtained by using the methods AxisXYZ.getAxisX() and AxisXYZ.getAxisY()and AxisXYZ.getAxisZ(). Each of the Axis3D nodes in turn creates additional child nodes, as seen in the diagram below.

Accessor methods can be chained together, so the x-axis line can be retrieved using

axis.getAxisX().getAxisLine()

The code to set the x-axis line to blue is

axis.getAxisX().getAxisLine().setLineColor(Color.blue)

Axis Layout

The layout of an AxisXYZ chart is controlled by the attributes Window and Number.

Attribute Window

Window is a double array-valued attribute that contains the axis limits. Its value is (min, max).

Attribute Number

Number is an integer-valued attribute that contains the number of major tick marks along an axis.

Transform

The x-, y- and z-axes may be linear or logarithmic, as specified by the Transform attribute. This attribute can have the values:

• TRANSFORM_LINEAR indicating a linear axis. This is the default.
• TRANSFORM_LOG indicating a logarithmic axis.

Autoscale

Autoscaling is used to automatically determine the attribute Window (the range of numbers along an axis) and the attribute Number (the number of major tick marks). The goal is to adjust the attributes so that the data fits on the axes and the axes have "nice" numbers as labels.

Autoscaling is done in two phases. In the first ("input") phase the actual range is determined. In the second ("output") phase chart attributes are updated.

Attribute AutoscaleInput

The action of the input phase is controlled by the value of attribute AUTOSCALE_INPUT in the axis node. It can have one of three values.

• AUTOSCALE_OFF turns off autoscaling.
• AUTOSCALE_DATA scans the values in the Data nodes that are attached to the axis to determine the data range. This is the default value.
• AUTOSCALE_WINDOW uses the value of the Window attribute to determine the data range.

Attribute AutoscaleOutput

The value of the AUTOSCALE_OUTPUT attribute can be the bitwise combination of the following values.

• AUTOSCALE_OFF no attributes updated.
• AUTOSCALE_NUMBER updates the value of the Number attribute. This is the number of major tick marks along the axis.
• AUTOSCALE_WINDOW updates the value of the Window attribute. This is the range of numbers displayed along the axis.

The default is AUTOSCALE_NUMBER | AUTOSCALE_WINDOW; both the attributes Number and Window are adjusted.

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