Return internal class.

Resolution of the spline. Resolution is the number of subdivisions by the step dimension for each segment. The default value is 32. The allowed value are [2 .. 1024].

Key of the value that should be interpreted as step dimension. Typically it is NChartValue.X (which is the default value), however for bar series it should be NChartValue.Y.

Key of the value that should be interpreted as height dimension. Typically it is NChartValue.Y (which is the default value), however for bar series it should be NChartValue.X.