Filters out all data points in a series except for a specified number of point's with the largest (first) Y-values. The Series object that is filtered is used to store the modified data.
Keeps only N top/bottom points of the series.
Syntax
| Visual Basic (Declaration) | |
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Public Overloads Sub FilterTopN( _ ByVal pointCount As Integer, _ ByVal inputSeries As Series _ ) | |
| Visual Basic (Usage) |  Copy Code |
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| C# | |
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public void FilterTopN( int pointCount, Series inputSeries ) | |
Parameters
- pointCount
- The number of data points that the filtering operation will not remove.
Number of top/bottom points to return. - inputSeries
- Series object that is filtered. It is also used to store the modified data.
Input series.
Example
| Visual Basic | Copy Code |
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Imports Dundas.Charting.WebControl<CRLF> ...<CRLF><CRLF>Dim currentDate As DateTime<CRLF>Dim randomValues As New Random()<CRLF>Dim i As Int32<CRLF><CRLF>' Initialize variables<CRLF>currentDate = DateTime.Now.Date<CRLF><CRLF>' Add randomly-sized data points to Series1<CRLF>For i = 0 To 20<CRLF> Chart1.Series("Series1").Points.AddXY(currentDate.AddDays(i), randomValues.Next(0, 100)<CRLF>Next<CRLF><CRLF>' Filter out all points except the 10 data points with the largest Y values<CRLF>Chart1.DataManipulator.FilterTopN(10, Chart1.Series("Series1")) | |
| C# | Copy Code |
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using Dundas.Charting.WebControl;<CRLF> ...<CRLF><CRLF>System.DateTime currentDate = DateTime.MinValue;<CRLF>Random randomValues = new Random();<CRLF>Int32 i = 0;<CRLF><CRLF>// Initialize variables<CRLF>currentDate = DateTime.Now.Date;<CRLF><CRLF>// Add randomly-sized data points to Series1<CRLF>for (i = 0; i <= 20; i++)<CRLF>{<CRLF> Chart1.Series["Series1"].Points.AddXY(currentDate.AddDays(i), randomValues.Next(0, 100);<CRLF>}<CRLF><CRLF>// Filter out all points except the 10 data points with the largest Y values<CRLF>Chart1.DataManipulator.FilterTopN(10, Chart1.Series["Series1"]); | |
Remarks
This method removes all data points from the input series except for a specified number of points that have the largest first Y-values. For example, this method can be used to retrieve the top five products by sales.
To filter a series:
- and keep data points with the smallest values use another definition of this function that uses a getTopValues argument.
- based on a data point value other than the first Y-value (e.g. "X", "Y2", "Y3", etc.) use another definition of this method that takes a usingValue argument.
- and preserve the original series use another definition of this function that uses an outputSeries argument.
Filtered points can be either removed from a series (default) or displayed as empty points, depending on the FilterSetEmptyPoints value.
Requirements
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