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api:dk11:net:tatukgis.ndk.tgis_classificationmethod

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TGIS_ClassificationMethod enum

DK11 for .NET | TatukGIS.NDK.TGIS_ClassificationMethod | Enums

Enumeration of classification methods.

Available also on: Delphi | Java | ActiveX.

Syntax

// C#
public enum TGIS_ClassificationMethod
{
  DefinedInterval, EqualInterval, GeometricalInterval, KMeans, KMeansSpatial, NaturalBreaks, 
  Quantile, Quartile, StandardDeviation, StandardDeviationWithCentral, Unique
}
' VisualBasic
Public Enum TGIS_ClassificationMethod
  DefinedInterval
  EqualInterval
  GeometricalInterval
  KMeans
  KMeansSpatial
  NaturalBreaks
  Quantile
  Quartile
  StandardDeviation
  StandardDeviationWithCentral
  Unique
End Enum
// Oxygene
type
  TGIS_ClassificationMethod = public (
    DefinedInterval, EqualInterval, GeometricalInterval, KMeans, KMeansSpatial, NaturalBreaks, 
    Quantile, Quartile, StandardDeviation, StandardDeviationWithCentral, Unique
  );

Members

Name Value Description
DefinedInterval The interval between class breaks is defined by the user through the Interval property. Number of classes is determined automatically and can be gotten from the NumClasses property.
EqualInterval The range of attribute values is partitioned into equal-sized subranges by defining the number of classes through the NumClasses property.
GeometricalInterval Class breaks are based on class intervals that have a geometrical series. User specifies the number of class intervals through the NumClasses property.
KMeans Class breaks are determined using the K-Means Clustering Algorithm. All values from an attribute are divided into N=NumClasses clusters so the within-cluster sum of squares is minimized.
KMeansSpatial K-Means algorithm is used to partition data into N=NumClasses spatial clusters based on objects centroids. Available only for vector layers. New field named 'KMEANS_ID' will be added or updated if it exists.
NaturalBreaks Class breaks are determined using the Fisher's Exact Optimization algorithm. Dataset is divided into N=NumClasses clusters so that the between-cluster sum of squares is maximized. This is default method.
Quantile Class intervals are created to have an equal number of observations. Number of classes can be defined through the NumClasses property. This method is also known as Equal Count.
Quartile Quantile method is applied with fixed property NumClasses=4. This method creates class breaks at the first, second, and third quartiles i.e. at 25-th, 50-th, and 75-th percentiles respectively.
StandardDeviation Class breaks are set above and below the mean of the attribute values at intervals, for example at 1, 1/2, 1/3, or 1/4 standard deviations until all the data values are contained within these ranges. Interval is specified through the Interval property. This method produces even number of classes.
StandardDeviationWithCentral Same as StandardDeviation but class breaks are shifted by a half of the interval to get central class in range [Mean-Interval/2..Mean+Interval/2]. For example, if Interval equals 1 Std Dev, central class is limited by breaks -0.5 Std Dev and 0.5 Std Dev. This method produces odd number of classes.
Unique Class breaks are set for unique values. Number of classes can be limited through the NumClasses property.

Remarks

K-Means Spatial

By default, KMeansSpatial classification method works with 2-dimensional data - using objects' centroids (X, Y).

To perform an algorithm in 3D, set Field property with Z-data. You can use one of the built-in fields, such as GIS_COORD_Z, GIS_CENTER_Z, or any numerical existing field.

2021/01/14 01:17

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