This topic describes some important terms used in the Nevron Chart for .NET series documentation.
Series as a term represents a union of chart data and presentation logic for a specific charting type. You may think of series as the primary building blocks of the chart. For example a pie chart is created with only one series of type NPieSeries, but a stacked area chart consists of several NAreaSeries , which are visualized on top of each other.
Data Series are collections that contain uniform data. Data series are used by the series to store the chart data. For example a point series needs x, y and z values in order to display a XYZ scatter, so it has one data series for the elevation values, another one for the x-values and a third one for the z-values. There are two types of data series with regard to the way they store the data: array data series and indexed data series.
An array data series is a one dimensional array based on the ArrayList collection. It is represented by the NDataSeries type and is used to store simple data types like double, bool and string.
An indexed data series resembles a map collection - its items are index-to-value pairs. It is represented by the NIndexedDataSeries and NIndexedAttributeSeries types. NIndexedAttributeSeries is used to store complex data types like NFillStyle, NStrokeStyle, NInteractivityStyle, NMarkerStyle, NDataLabelStyle.
The operations for inserting objects in the data series are type safe, which means that the component will throw an exception if you try to insert an object of type that is incompatible with the type of the data series. The following table summarizes the compatibility of the data series types:
Type | Compatible Types |
---|---|
Double | System.Double, System.Single, System.Decimal, System.String (parsable double value), System.DateTime, System.Int16, System.Int32, System.Int64, DBNull.Value (used for empty data points) |
String | System.String, System.Object |
Bool | System.Boolean, System.String (parsable boolean value) |
FillStyle | NFillStyle and derived types, System.Drawing.Color, System.String (parsable color), DBNull.Value, System.Int32 (argb value) |
StrokeStyle | NStrokeStyle , System.Drawing.Color, System.String (parsable color), DBNull.Value, System.Int32 (argb value) |
InteractivityStyle | NInteractivityStyle |
MarkerStyle | NMarkerStyle |
DataLabelStyle | NDataLabelStyle |
The double and string values contained in a data series can be displayed in the data labels and in the chart legend. The format of a double value defines the string representation of the value. It is controlled by a corresponding NValueFormatter object assigned to each data series. It is accessible through the ValueFormatter property of the NDataSeries object.
Data Point is a logical union of values that belong to different data series and have the same index. Usually the data points have visual representation in the chart. For example a stock chart data point consists of four values: open, high, low and close. The combination of these four values is visually represented as a stock candle.
Data points are not physically stored as objects, but are assembled "on the fly" from the data series. When you operate on the series data you can choose either to work with data points or to work directly with the data series. The NSeries class implements the INDataPointCollection interface that represents the series data as a collection of data point objects. The assembling of the data points is discussed in detail for each individual series.