Jenness Enterprises - ArcView Extensions; Mahalanobis Distances

Mexican Spotted Owl, stretching...

The Mahalanobis Distances extension won 1st place in the Avenue category of the User Applications Software Fair; 2004 ESRI International User Conference, San Diego, CA, USA.

NAME: Mahalanobis Distances (Click Name to Download)

Adobe PDF Version of Manual: Mahalanobis Manual (1.51 mb)

View and Download Mahalanobis Poster

Aka: Mahalanobis.avx

Last modified: December 9, 2003
Manual modified May 4, 2004

TOPICS: Mahalanobis, statistic, correlation, covariance, mean, matrix, distance, Pearson, Spearman, rho, landscape wildlife

AUTHOR: Jeff Jenness
     Wildlife Biologist, GIS Analyst
     Jenness Enterprises
     3020 N. Schevene Blvd.
     Flagstaff, AZ 86004 USA
     jeffj@jennessent.com

DESCRIPTION: This extension produces several possible Mahalanobis-related outputs:

	The View button generates a Mahalanobis surface grid based on independent variable grids (see Mahalanobis Distance Grids).
	The View button recodes a Mahalanobis surface grid into a p-value grid based on a Chi-Square distribution with n-1 degrees of freedom, where n = # independent variable grids used to generate the Mahalanobis grid (see Mahalanobis Chi-Square Tools).
	The View button generates a Results table of Mahalanobis distances for each feature in a point, line or polygon theme (see Mahalanobis Theme Distances).
	The View tool allows you to click on a Mahalanobis surface grid cell and calculate the Chi-square p-value for that cell. The p-values are reported in a text window (see Mahalanobis Chi-Square Tools).
	The Table button generates a new field in the current table containing Mahalanobis distances for each record in the table (see Mahalanobis Table Distances).
	The Table button generates tables containing mean vectors, covariance matrices, inverse covariance matrices, and correlation matrices for numeric fields in the current table (see Mahalanobis Statistical Matrices).

Please see Mahalanobis Description for a discussion of Mahalaobis distances in general.

REQUIRES: ArcView 3.x and Spatial Analyst. The extension will not load if Spatial Analyst is not present.

This extension also requires that the file "avdlog.dll" be present in the ArcView/BIN32 directory (or $AVBIN/avdlog.dll) and that the Dialog Designer extension be located in your ArcView/ext32 directory, which they usually are if you're running AV 3.1 or better. The Dialog Designer doesn't have to be loaded; it just has to be available. If you are running AV 3.0a, you can download the appropriate files for free from ESRI at:

http://support.esri.com/index.cfm?fa=downloads.patchesServicePacks.viewPatch&PID=25&MetaID=483

Recommended Citation Format: For those who wish to cite this extension, the author recommends something similar to:

Jenness, J. 2003. Mahalanobis distances (mahalanobis.avx) extension for ArcView 3.x, Jenness Enterprises. Available at: http://www.jennessent.com/arcview/mahalanobis.htm.

Please let me know if you cite this extension in a publication (jeffj@jennessent.com). I will update the citation list to include any publications that I am told about.

Using the Mahalanobis Distances Extension:

Begin by placing the " mahalanobis.avx" file into the ArcView extensions directory (../../Av_gis30/Arcview/ext32/).
After starting ArcView, load the extension by clicking on File --> Extensions… , scrolling down through the list of available extensions, and then clicking the checkbox next to "Mahalanobis Distances."

Each Mahalanobis operation is described in detail in the following pages:

Download Extension | Download Manual

Enjoy! Please contact the author if you have problems or find bugs.

Jeff Jenness jeffj@jennessent.com

3020 N. Schevene Blvd.

Flagstaff, AZ 86004

USA

Please visit Jenness Enterprises ArcView Extensions site for more ArcView Extensions and other software by the author. We also offer customized ArcView-based GIS consultation services to help you meet your specific data analysis and application development needs.