TGIS_StatisticsAbstract class

DK for ActiveX | TatukGIS_XDK11.TGIS_StatisticsAbstract | Classes | Methods | Properties

General statistics class. Must be derived.

Available also on: Delphi | .NET | Java | Python.

// C#
public class TGIS_StatisticsAbstract : ITGIS_StatisticsAbstract 
{
}

' VisualBasic
Public Class TGIS_StatisticsAbstract
  Implements ITGIS_StatisticsAbstract
End Class

// Oxygene
type
  TGIS_StatisticsAbstract = public class
  end;

ITGIS_StatisticsAbstract

This class provide access to generating, saving and loading layer's statistics.

TGIS_StatisticalFunction enum contains a list of available statistical functions. These functions are also presented in the table below.

TGIS_StatisticalFunctions is used to define requested statistics. Predefined groups can be used:

• EmptyStatistics,
• BasicStatistics,
• StandardStatistics (this is default),
• AllStatistics.

Statistical results can be narrowed by setting Extent, Shape, Relation properties.

By default, the statistics engine calculates population standard deviation and variance (divider equals “N”). Sample variance and standard deviation (divider equals “N-1”) can be calculated by setting UseBesselCorrection to True.

See:

• TGIS_StatisticalFunction
• TGIS_StatisticalFunctions
• TGIS_StatisticsVector
• TGIS_StatisticsPixel

Pseudocode:

// add all fields from vector layer or bands from pixel layer
layer.Statistics.AddAll(TGIS_StatisticalFunctions.BasicStatistics);

layer.Statistics.Calculate;

// demand a result
stats_result = layer.Statistics.Get(<valid_name>);

Valid names are listed in the stats.AvailableResults list.

// check calculated values
average = stats_result.Average.Value;
count = stats_result.Count.Value;
min = stats_result.Min.Value;
max = stats_result.Max.Value;
sum = stats_result.Sum.Value;

• JupyterNotebookDKForPython sample
• LayerStatistics sample