com.esri.arcgis.geoprocessing.tools.spatialstatisticstools
Class DirectionalDistribution

java.lang.Object
  com.esri.arcgis.geoprocessing.AbstractGPTool
      com.esri.arcgis.geoprocessing.tools.spatialstatisticstools.DirectionalDistribution

All Implemented Interfaces:

GPTool

public class DirectionalDistribution
extends AbstractGPTool

Creates standard deviational ellipses to summarize the spatial characteristics of geographic features: central tendency, dispersion, and directional trends. The Directional Distribution (Standard Deviational Ellipse) tool is contained in the Spatial Statistics Tools tool box.

Usage tips:

• The Standard Deviational Ellipse tool creates a new Output Feature Class containing elliptical polygons, one for each Case (Case Field parameter). The attribute values for these ellipse polygons include X and Y coordinates for the mean center, two standard distances (long and short axes), and the orientation of the ellipse. The fieldnames are CenterX, CenterY, XStdDist, YStdDist, and Rotation. When a Case Field is provided, this field is added to the Output Feature Class, as well.
• Calculations based on either Euclidean or Manhattan distance require to accurately measure distances.
• When the underlying spatial pattern of features is concentrated in the center with fewer features toward the periphery (a spatial normal distribution), a one standard deviation ellipse polygon will cover approximately 68 percent of the features; two standard deviations will contain approximately 95 percent of the features; and three standard deviations will cover approximately 99 percent of the features in the cluster.
• The value in the output Rotation field represents the rotation of the long axis measured clockwise from noon.
• The Case Field is used to group features prior to analysis. When a Case Field is specified, the input features are first grouped according to case field values, and then a standard deviational ellipse is computed for each group. The case field can be of numeric, date, or string type.
• The standard deviational ellipse calculation may be based on an optional Weight Field (to get the ellipses for traffic accidents weighted by severity, for example). The Weight Field should be numeric.
• For line and polygon features, feature centroids are used in distance computations. For multipoints, polylines, or polygons with multiple parts, the centroid is computed using the weighted mean center of all feature parts. The weighting for point features is 1, for line features is length, and for polygon features is area.
• Map layers can be used to define the Input Feature Class. When using a layer with a selection, only the selected features are included in the analysis.
• When using shapefiles, keep in mind that they cannot store null values. Tools or other procedures that create shapefiles from non-shapefile inputs may store or interpret null values as zero. This can lead to unexpected results. See also .

Field Summary

Fields inherited from class com.esri.arcgis.geoprocessing.AbstractGPTool

vals

Constructor Summary

DirectionalDistribution()
Creates the Directional Distribution (Standard Deviational Ellipse) tool with defaults.

DirectionalDistribution(java.lang.Object inputFeatureClass, java.lang.Object outputEllipseFeatureClass, java.lang.String ellipseSize)
Creates the Directional Distribution (Standard Deviational Ellipse) tool with the required parameters.

Method Summary

java.lang.Object	getCaseField() Returns the Case Field parameter of this tool .
java.lang.String	getEllipseSize() Returns the Ellipse Size parameter of this tool .
java.lang.Object	getInputFeatureClass() Returns the Input Feature Class parameter of this tool .
java.lang.Object	getOutputEllipseFeatureClass() Returns the Output Ellipse Feature Class parameter of this tool .
java.lang.String	getToolboxAlias() Returns the alias of the tool box containing this tool.
java.lang.String	getToolboxName() Returns the name of the tool box containing this tool.
java.lang.String	getToolName() Returns the name of this tool.
java.lang.Object	getWeightField() Returns the Weight Field parameter of this tool .
void	setCaseField(java.lang.Object caseField) Sets the Case Field parameter of this tool .
void	setEllipseSize(java.lang.String ellipseSize) Sets the Ellipse Size parameter of this tool .
void	setInputFeatureClass(java.lang.Object inputFeatureClass) Sets the Input Feature Class parameter of this tool .
void	setOutputEllipseFeatureClass(java.lang.Object outputEllipseFeatureClass) Sets the Output Ellipse Feature Class parameter of this tool .
void	setWeightField(java.lang.Object weightField) Sets the Weight Field parameter of this tool .

Methods inherited from class com.esri.arcgis.geoprocessing.AbstractGPTool

getParameterValues, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

DirectionalDistribution

public DirectionalDistribution()

Creates the Directional Distribution (Standard Deviational Ellipse) tool with defaults.

Initializes the array of tool parameters with the default values specified when the tool was created.

DirectionalDistribution

public DirectionalDistribution(java.lang.Object inputFeatureClass,
                               java.lang.Object outputEllipseFeatureClass,
                               java.lang.String ellipseSize)

Creates the Directional Distribution (Standard Deviational Ellipse) tool with the required parameters.

Initializes the array of tool parameters with the values as specified for the required parameters and with the default values for the other parameters.

Parameters:

inputFeatureClass - a feature class containing a distribution of features for which the standard deviational ellipse will be calculated.

outputEllipseFeatureClass - a polygon feature class that will contain the output ellipse feature.

ellipseSize - the size of output ellipses in standard deviations. The default ellipse size is 1; valid choices are 1, 2, or 3 standard deviations.

Method Detail

getInputFeatureClass

public java.lang.Object getInputFeatureClass()

Returns the Input Feature Class parameter of this tool . This parameter is a feature class containing a distribution of features for which the standard deviational ellipse will be calculated. This is a required parameter.

Returns:

the Input Feature Class

setInputFeatureClass

public void setInputFeatureClass(java.lang.Object inputFeatureClass)

Sets the Input Feature Class parameter of this tool . This parameter is a feature class containing a distribution of features for which the standard deviational ellipse will be calculated. This is a required parameter.

Parameters:

inputFeatureClass - a feature class containing a distribution of features for which the standard deviational ellipse will be calculated.

getOutputEllipseFeatureClass

public java.lang.Object getOutputEllipseFeatureClass()

Returns the Output Ellipse Feature Class parameter of this tool . This parameter is a polygon feature class that will contain the output ellipse feature. This is a required parameter.

Returns:

the Output Ellipse Feature Class

setOutputEllipseFeatureClass

public void setOutputEllipseFeatureClass(java.lang.Object outputEllipseFeatureClass)

Sets the Output Ellipse Feature Class parameter of this tool . This parameter is a polygon feature class that will contain the output ellipse feature. This is a required parameter.

Parameters:

outputEllipseFeatureClass - a polygon feature class that will contain the output ellipse feature.

getEllipseSize

public java.lang.String getEllipseSize()

Returns the Ellipse Size parameter of this tool . This parameter is the size of output ellipses in standard deviations. The default ellipse size is 1; valid choices are 1, 2, or 3 standard deviations. This is a required parameter.

Returns:

the Ellipse Size

setEllipseSize

public void setEllipseSize(java.lang.String ellipseSize)

Sets the Ellipse Size parameter of this tool . This parameter is the size of output ellipses in standard deviations. The default ellipse size is 1; valid choices are 1, 2, or 3 standard deviations. This is a required parameter.

Parameters:

ellipseSize - the size of output ellipses in standard deviations. The default ellipse size is 1; valid choices are 1, 2, or 3 standard deviations.

getWeightField

public java.lang.Object getWeightField()

Returns the Weight Field parameter of this tool . This parameter is the numeric field used to weight locations according to their relative importance. This is an optional parameter.

Returns:

the Weight Field

setWeightField

public void setWeightField(java.lang.Object weightField)

Sets the Weight Field parameter of this tool . This parameter is the numeric field used to weight locations according to their relative importance. This is an optional parameter.

Parameters:

weightField - the numeric field used to weight locations according to their relative importance.

getCaseField

public java.lang.Object getCaseField()

Returns the Case Field parameter of this tool . This parameter is field used to group features for separate directional distribution calculations. The case field can be of numeric, date, or string type. This is an optional parameter.

Returns:

the Case Field

setCaseField

public void setCaseField(java.lang.Object caseField)

Sets the Case Field parameter of this tool . This parameter is field used to group features for separate directional distribution calculations. The case field can be of numeric, date, or string type. This is an optional parameter.

Parameters:

caseField - field used to group features for separate directional distribution calculations. The case field can be of numeric, date, or string type.

getToolName

public java.lang.String getToolName()

Returns the name of this tool.

Returns:

the tool name

getToolboxName

public java.lang.String getToolboxName()

Returns the name of the tool box containing this tool.

Returns:

the tool box name

getToolboxAlias

public java.lang.String getToolboxAlias()

Returns the alias of the tool box containing this tool.

Returns:

the tool box alias