Elements And Axis Scales

Introduction

While there are many options for scales, .netCHARTING can automatically determine the appropriate scales based on your data. This tutorial will demonstrate how element data influences axis scales.

The Y Axis ( value axis )

We will call this the y axis but by 'value axis' we don't literally mean (Y) axis. With ChartType.ComboHorizontal for instance we would be referring to the x axis. For all others however it is the y axis. The element values that influence this axis are

YValue
YValueStart
YDateTime
YDateTimeStart

[New in v5.0]
The elements of a series can be excluded from the axis scale range using Series.ExcludeFromAxisRange = true

The automatically chosen axis scales here are either Normal or Time. It is determined by whether the YValue (numeric) or YDateTime (time) values are specified for each element.

The following table shows value settings of these element properties that the chart engine will consider not set.

YValue & YValueStart
Setting: double.NaN
YDateTime & YDateTimeStart
Setting: DateTime.MinValue

The X Axis (Category / Value Axis)

Y Axis using ChartType.ComboHorizontal

The x axis is very powerful, it can operate just like the y axis value axis as well as a category axis. If the elements have names (Element.Name) specified, the axis scale will be a category scale. However, if the elements have either XValue or XDateTime properties set, the appropriate value axis scale will be chosen.

The element properties that influence the x axis type are:

Name
XValue
XValueStart
XDateTime
XDateTimeStart

Even if all numeric or time values are provided, setting any of the element's Name properties will yield a category axis scale and values will become names for elements without specified names.

The data engine will always provide elements with both, names and values if the names represent numeric or time values. By default this creates a category scale. To use a value scale instead, set the axis scale property to the appropriate scale. Scale.Normal for numeric and Scale.Time for date time values.

Setting the scale through DefaultAxis.Scale will not produce the same result.

Smart Category Axis

A scale is one that contains elements with names and values but the names are string representations of the value properties. The 'smart' part is that despite it being a category (string) axis, the elements will be sorted in sequence based on the values they represent.

To use this axis type you must use the DataEngine and specify 'XAxis=valueDBColumn' in its DataFields property.

Tutorials

Data Field Mapping

Data Engine