Public Overloads Sub Group( _
   ByVal formula As String, _
   ByVal interval As Double, _
   ByVal intervalType As IntervalType, _
   ByVal inputSeries As Series, _
   ByVal outputSeries As Series _
) 

Visual Basic (Usage)	Copy Code
Dim instance As DataManipulator Dim formula As String Dim interval As Double Dim intervalType As IntervalType Dim inputSeries As Series Dim outputSeries As Series   instance.Group(formula, interval, intervalType, inputSeries, outputSeries)

public void Group( 
   string formula,
   double interval,
   IntervalType intervalType,
   Series inputSeries,
   Series outputSeries
)

Parameters

formula

The formula(s) to be used for calculating the "grouped" data point values. Multiple formulas can be specified by using comma-separated values.
Grouping formula.

interval

Determines the grouping intervals.
Interval size.

intervalType

Determines the unit of measurement for the grouping intervals.
Interval type.

inputSeries

The series  that will be grouped.
Input data series.

outputSeries

The series that will store the new data points created by the grouping operation. If the specified series does not exist an exception will be thrown.
Output data series.

This method divides a series' data points into intervals and replaces the points in each interval with a new data point. The applied formula(s) determine the x and Y-values of these new points.

The interval and intervalType parameters determine the intervals. For example, let's assume that there are numerous data points that are plotted at random for an entire year. To group those points together on a monthly basis the interval would be one (1) and the intervalType would be "IntervalType.Month". To group them by yearly quarters the interval would be three (3) and the intervalType would be "IntervalType.Month".

The first formula is the default, and is applied to all Y-values that are not calculated using subsequent formulas. Formulas specified after the default formula must have a "value" prefix to identify which value they should be applied to. For example, an expression of "SUM, Y2:AVE, X:CENTER" means that an average of secondary Y-values will be calculated, a sum of all other Y-values will be calculated and the resulting data points will be plotted in the middle of their intervals. See Table1  for a listing of possible formulas and their descriptions.

Formulas for X-values merely determine where resulting data points will be plotted for the specified interval (e.g. along the left or right boundary of an interval or in the center of the interval). By default a formula of "FIRST" will be used for X-values (data point is plotted at the left of the interval).

If the specified output series has not been created and added to the SeriesCollection when this function call is made an exception will be thrown.

All data points in the given series are grouped (i.e. it is not possible to group only some of a series' data points).

Empty data points will be ignored or treated as zeros, depending on the IgnoreEmptyPoints property (by default IgnoreEmptyPoints is True).

Table 1: Formulas.

Target Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, Windows Vista, Windows Server 2008 family

Reference