This example demonstrates a RadHtmlChart control, configured as an Area Chart (it uses AreaSeries),
which can be used for displaying categorical data.
Spline (Smooth) and Step Line appearance of the series can be
configured via the LineStyle property in the LineAppearance tag since Q1 2014 by
choosing one of the options from the ExtendedLineStyle enumeration:
Normal — the default series appearance.
Step — the individual series items are connected with vertical and horizontal lines to form a step-like progression.
Smooth — the series items are connected with a fitted curve which represents a rough approximation of the missing data points.