Show Navigation | Hide Navigation
You are here:
Geoprocessing tool reference > Spatial Statistics toolbox > Analyzing Patterns toolset > Tools

Multi-Distance Spatial Cluster Analysis (Ripley's k-function) (Spatial Statistics)

Release 9.2
Last modified January 9, 2009
E-mail This Topic Printable Version Give Us Feedback

Print all topics in : "Tools"


Related Topics

The Multi-Distance Spatial Cluster Analysis (Ripley's K-function) tool determines whether a feature class is clustered at multiple different distances. The tool outputs the result as a table and optionally as a pop up graphic.

Learn more about how Multi-Distance Spatial Cluster Analysis works.


Usage tips

Command line syntax
An overview of the Command Line window
MultiDistanceSpatialClustering_stats <Input_Feature_Class> <Output_Table> <Number_of_Distance_Bands> {0 Permutations - no confidence envelope | 9 Permutations | 99 Permutations | 999 Permutations} {Display_Results_Graphically} {Weight_Field} {Beginning_Distance} {Distance_Increment} {None | Simulate Outer Boundary Values | Reduce Analysis Area | Ripley's Edge Correction Formula} {Minimum Enclosing Rectangle | User provided Study Area Feature Class} {Study_Area_Feature_Class}

Parameter Explanation Data Type
<Input_Feature_Class>

The feature class upon which the analysis will be performed.

Feature Class
<Output_Table>

The table to which the results of the analysis will be written.

Table
<Number_of_Distance_Bands>

The number of times to increment the neighborhood size and analyze the dataset for clustering. The starting point and size of the increment are specified in the Beginning Distance and Distance Increment parameters respectively.

Long
{0 Permutations - no confidence envelope | 9 Permutations | 99 Permutations | 999 Permutations}

The confidence envelope is calculated by randomly placing points in the study area. The number of points randomly placed is equal to the number of points in the feature class. Each set of random placements is called a "permutation" and the confidence envelope is created from these permutations. This parameter allows you to select how many permutations you want to use to create the confidence envelope.

  • 0 Permutations: no confidence envelope — Confidence envelopes are not created.
  • 9 Permutations — the tool randomly places nine sets of points.
  • 99 Permutations — the tool randomly places 99 sets of points.
  • 999 Permutations — the tool randomly places 999 sets of points.

String
{Display_Results_Graphically}

Specifies whether the tool will display the results of the Multi-Distance Spatial Cluster Analysis tool graphically.

  • True — The output will be displayed graphically.
  • False — The output will not be displayed graphically.

Boolean
{Weight_Field}

A numeric field with weights that give certain features more influence than others.

Field
{Beginning_Distance}

The distance at which to start the cluster analysis and the distance from which to increment. The value entered for this parameter should be in the units of the Input Feature Class' coordinate system.

Double
{Distance_Increment}

The distance by which to increment during each iteration. The distance used in the analysis starts at the Beginning Distance and increments by the amount specified in the Distance Increment. The value entered for this parameter should be in the units of the Input Feature Class' coordinate system.

Long
{None | Simulate Outer Boundary Values | Reduce Analysis Area | Ripley's Edge Correction Formula}

Method to use to correct for under estimates in the number of neighbors for features near the edges of the study area.

  • None — Points outside the study area are not placed to reduce underestimation. However, if the input feature class already has points that fall outside of the study area, these will be used in neighborhood counts (but not for the k-function calculation).
  • Simulate Outer Boundary Values — This method simulates points outside the study area so that the number of neighbors near the edges is not under estimated. The simulated points are the "mirrors" of points within the study area across the study area boundary.
  • Reduce Analysis Area — This method shrinks the study area such that some points are found outside of the study area. Points found outside the study area are used to calculate neighbor counts but not used in the cluster analysis itself.
  • Ripley's Edge Correction Formula — For all the points (j) in the neighborhood of point i, this method checks to see if the edge of the study area is closer to i or if j is closer to i. If j is closer, extra weight is given to the point j. This edge correction method is only appropriate for square or rectangular shaped study areas.

String
{Minimum Enclosing Rectangle | User provided Study Area Feature Class}

Specifies the region to use for the study area. Selection of this area is critical as area is part of the equation used by the tool.

  • Minimum Enclosing Rectangle — Indicates that the smallest possible rectangle enclosing all of the points will be used.
  • User provided Study Area Feature Class — Indicates that a feature class defining the study area will be provided in the Study Area Feature Class parameter.

String
{Study_Area_Feature_Class}

Feature class that delineates the area over which the input feature class should be analyzed. Only to be specified if User-provided Study Area Feature Class is specified in the Study Area Feature Class parameter.

Feature Class
Data types for geoprocessing tool parameters


Command line example

MultiDistanceSpatialClusterAnalysis

Scripting syntax
About getting started with writing geoprocessing scripts
MultiDistanceSpatialClustering_stats (Input_Feature_Class, Output_Table, Number_of_Distance_Bands, Compute_Confidence_Envelope, Display_Results_Graphically, Weight_Field, Beginning_Distance, Distance_Increment, Boundary_Correction_Method, Study_Area_Method, Study_Area_Feature_Class)

Parameter Explanation Data Type
Input_Feature_Class (Required)

The feature class upon which the analysis will be performed.

Feature Class
Output_Table (Required)

The table to which the results of the analysis will be written.

Table
Number_of_Distance_Bands (Required)

The number of times to increment the neighborhood size and analyze the dataset for clustering. The starting point and size of the increment are specified in the Beginning Distance and Distance Increment parameters respectively.

Long
Compute_Confidence_Envelope (Optional)

The confidence envelope is calculated by randomly placing points in the study area. The number of points randomly placed is equal to the number of points in the feature class. Each set of random placements is called a "permutation" and the confidence envelope is created from these permutations. This parameter allows you to select how many permutations you want to use to create the confidence envelope.

  • 0 Permutations: no confidence envelope — Confidence envelopes are not created.
  • 9 Permutations — the tool randomly places nine sets of points.
  • 99 Permutations — the tool randomly places 99 sets of points.
  • 999 Permutations — the tool randomly places 999 sets of points.

String
Display_Results_Graphically (Optional)

Specifies whether the tool will display the results of the Multi-Distance Spatial Cluster Analysis tool graphically.

  • True — The output will be displayed graphically.
  • False — The output will not be displayed graphically.

Boolean
Weight_Field (Optional)

A numeric field with weights that give certain features more influence than others.

Field
Beginning_Distance (Optional)

The distance at which to start the cluster analysis and the distance from which to increment. The value entered for this parameter should be in the units of the Input Feature Class' coordinate system.

Double
Distance_Increment (Optional)

The distance by which to increment during each iteration. The distance used in the analysis starts at the Beginning Distance and increments by the amount specified in the Distance Increment. The value entered for this parameter should be in the units of the Input Feature Class' coordinate system.

Long
Boundary_Correction_Method (Optional)

Method to use to correct for under estimates in the number of neighbors for features near the edges of the study area.

  • None — Points outside the study area are not placed to reduce underestimation. However, if the input feature class already has points that fall outside of the study area, these will be used in neighborhood counts (but not for the k-function calculation).
  • Simulate Outer Boundary Values — This method simulates points outside the study area so that the number of neighbors near the edges is not under estimated. The simulated points are the "mirrors" of points within the study area across the study area boundary.
  • Reduce Analysis Area — This method shrinks the study area such that some points are found outside of the study area. Points found outside the study area are used to calculate neighbor counts but not used in the cluster analysis itself.
  • Ripley's Edge Correction Formula — For all the points (j) in the neighborhood of point i, this method checks to see if the edge of the study area is closer to i or if j is closer to i. If j is closer, extra weight is given to the point j. This edge correction method is only appropriate for square or rectangular shaped study areas.

String
Study_Area_Method (Optional)

Specifies the region to use for the study area. Selection of this area is critical as area is part of the equation used by the tool.

  • Minimum Enclosing Rectangle — Indicates that the smallest possible rectangle enclosing all of the points will be used.
  • User provided Study Area Feature Class — Indicates that a feature class defining the study area will be provided in the Study Area Feature Class parameter.

String
Study_Area_Feature_Class (Optional)

Feature class that delineates the area over which the input feature class should be analyzed. Only to be specified if User-provided Study Area Feature Class is specified in the Study Area Feature Class parameter.

Feature Class

Data types for geoprocessing tool parameters


Script example

(Enter the scripting example code here. Wrap the entire field with the Code formatting style. Format the comments in your code using Code Comment formatting style.)

Please visit the Feedback page to comment or give suggestions on ArcGIS Desktop Help.
Copyright © Environmental Systems Research Institute, Inc.