Chart Axes Attributes

Introduction

Charts are drawn into XYZ-coordinate system. Each axis attributes can be defined separately using the <axis> tag or the default values for all the axes can be set for the nesting <axes> tag. In the Chart XML the axes are defined like:

<axes default_attributes_here >
<axis dim="x" X-axis_specific_attributes_here />
<axis dim="y" Y-axis_specific_attributes_here />
<axis dim="z" Z-axis_specific_attributes_here />
</axes>

The axis dimension can be defined in three ways:

by coordinate axis names: "x", "y", and "z"
by coordinate axis index: "0", "1", and "2"
by logical axis names: "category", "value", and "series"

Logical names are useful when switching between bar and column charts. Logical "category" axis is mapped to Y-axis in bar chart and to X-axis in column chart. Coordinate and logical names cannot be mixed.

Angles

Modify the axis angle attribute to render charts in isometric 3D mode, to change the viewing angle for 3D charts, or to alter the start of the first pie slice. The positive rotation directions are shown in the picture below.

Axis directions

Z-axis rotation has effect only on pie and real 3D charts. In particular, pie slices are stacked around the pie hub in the positive Z -axis rotation direction, starting from the pie Z -axis angle. Pie slice stacking order can also be reversed by reversing pie Z -axis direction with axis reversed attribute. The zero angle and positive rotation direction for pie charts are shown below.

Pie direction.

Combo Charts

In combo charts each chart type has axes of its own. By default all axes groups have the same <plot/>, but each axes group can have it's own <plot/> attributes. The category and value axes of all combined charts are made uniform by default. If different min, max, step, or opposite values are given for axes, the axes are rendered separately.

Axis Control

The direction and facing of each axis can be controlled independently with reversed and opposite boolean axis attributes. Default values (false) give standard mathematical coordinate axes, with X- and Y- axes growing left and up, and scale values running below and left.

Axis Markers

Certain point along an axis may be highlighted with an axis marker. Any number of markers may be defined, and each marker will hightlight exactly one point.

The exact marker visualization depends on the chart type in question, but in each case the marker is associated with a label text, a symbol, and a line that divides the axis range into values smaller and greater than the given marker position value.

Examples

An isometric 3D column chart..

Custom axes and grid lines.

A combo chart with separated Y-axes.

Default axis positions and directions.

Reversed X-axis and opposite Y-axis.

Opposite X-axis and reversed Y-axis.

Reversed and opposite axes.

Marker lines and areas.