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FRAGSTATS: Spatial Pattern Analysis Program for Categorical Maps

Release Notes


This page is where you go to review the release notes. This page provides an up-to-date listing of all corrections and improvements made to the software associated with each new release.

Version Date Description
4.2(build 1/23/2015

Minor patch to version 4.2 (build to fix the following issues:

1. Fix error in the help files that prevented the figures/images from displaying.

2. Fix error in the uniform tiles sampling option that resulted in extraneous cells with values equal to zero and tiles that varied slightly in the number of cells.

4.2(build 10/1/2014

Minor patch to version 4.2 (build to fix the following issue:

1. Fix bug that resulted in incorrect PERIM_LSD values under special cases when the patch perimeters were very large.

4.2(build 4.2.598) 2/27/2014

Minor patch to version 4.2 (build 4.2.598) to fix two issues:

1. Fix bug that prevented the outputting of various grids (e.g., the patch ID file, uniform tiles, etc.) with the GeoTIFF data format.

2. Added a 'delete' button to the Input layers - Common tables tab of the user interface to allow users to delete entries for any of the common tables.

4.2(build 4.2.597) 1/16/2014 Minor patch to version 4.2 (build 4.2.597) to address the non-square cell issue. Specifically, for input data formats that include a header (e.g. geotiff), FRAGSTAT now accepts cells that exhibit differences between height and width less than 0.1%. This means that cells need to be approximately square, usually out to several decimal places. With respect to ESRI ArcGrids, FRAGSTATS cannot accept anything but perfectly square cells (see FAQ for the reasons why).
4.2(build 4.2.592) 12/10/2013

Minor patch to version 4.2 (build 4.2.592) with the following changes:

1. Fix help files to include figures 6 and 7, which were accidentally missing in the previous build.

2. Fix a bug that prevented the inclusion of the total edge constrast index (TECI) in the saved model file (.fca)(i.e., checking the box for TECI did not result in it being saved in the model file).

4.2(build 4.2.591 11/14/2013

Minor patch to version 4.2 (build 4.2.591) with the following changes:

1. For grids that are too large to analyze, FRAGSTATS now reports a descriptive error message to the activity log (instead of the vague error message previously reported).

2. For geotiffs with a previously invalid nodata values (i.e., an absolute value that exceeds the precision of a 32-bit integer), FRAGSTATS now accepts the value by converting to a valid value.

Tutorial (v2) 11/04/2013 Updated set of tutorials to reflect the release of version 4.2. In particular, added a tutorial (#6) to illustrate the use of the new sampling options for analyzing sub-landscapes.
4.2(build 4.2.589) 11/04/2013

First release of version 4.2 (build 4.2.589) that incorporates several options for sampling landscapes to analyze sub-landscapes.

Fixed a bug in the Interspersion and Juxtaposition Index (IJI) regarding the inclusion of patch types exclusively in the landscape border; the revision correctly counts patch types found exclusively in the border (i.e., negative cells along the landscape boundary) in the denominator (m) of the formula for IJI.

Related to above, changed the border to always include only a single cell with a negative class value along the landscape boundary and sharing a full side with a cell inside the landscape (i.e., with a positive cell value).

Fixed a bug that caused the program to crash when re-loading very large grids within the same session.

4.1(build 2) 9/14/2012 Second release of version 4.1 (build 4.1.444) that fixes a couple of issues causing program crashes: 1) class descriptor files with extra blank lines no longer causes a program crash; 2) extremely large core area patches no longer causes a program crash.
4.1(build 1) 8/20/2012 First release of version 4.1 that accommodes several new input image formats via the GDAL library.
4.0(build 4) 6/4/2012 Minor bug fix to fourth candidate release of version 4.0; fixed a bug that caused the program crash in a batch run if one of the unput landscapes did not contain any enabled class.
Diagnostic utility 6/1/2012 Improvement to the diagnostic utility to give a bit more information on each stage of checking out an ArcGIS spatial analyst license for ArcGrid users.
4.0(build 4) 5/30/2012 Fourth candidate release of version 4.0 with improvements to the reporting of invalid ArcGrids to the activity log, for example associated with invalid grid names or grids too large given the system's available memory.
Tutorial (v1) 5/28/2012 Update to the tutorial with more explicit instructions in Tutorial #1 regarding updating the system's environmental "path" variable and ensuring that ArcGrids are located in folders that do NOT contain spaces in their full path, and instructions for what to do if you get an error when trying open FRAGSTATS in tutorial #2.
4.0(build 3) 5/2/2012 Third candidate release of version 4.0 with our latest attempt to resolve conflicts with varying installations of ESRI ArcGIS. Hopefully, this version will work with any version of ArcGIS 10 or earlier, and with or without ArcInfo Workstation. However, ArcGrid users must have a valid ArcGIS license that includes Spatial Analyst.
4.0(build 2) 4/25/2012

Second candidate release of version 4.0 with a number of fixes to problems reported with the first release, including the following:

1) Fixed a bug in the results dialog that caused the first run in the run list to be deleted regardless of which run was selected when selecting the "drop selected run" option.

2) Modified the run timer to begin when the user clicks on the "proceed" button (which is the actual start of the run) instead of when the user first clicks on the "run" button.

3) Regorganized the layout of the Aggregation metrics at the patch and landscape levels to make clear the association of the search radius parameter with the proximity and similarity indices.

4) Fixed a bug in importing batch files that prevented the batch file from being read properly, resulting in a terminated execution.

5) Modified the protocol for folder navigation to start from the last non-cancelled location.

6) Fixed a bug in the moving window analysis that resulted in an improper nodata value in the landscape buffer.

7) Modified the patch id and moving window output grid file naming convention for ascii and binary formats to respect the extension convention (i.e., added .asc and .raw, respectively, to the file names).

4.0(build 1) 4/8/2012 First candidate release of version 4.0.
3.4(build 1)

Update for all users with the following change:

1) Modified to work with Arc Grids and version ArcGIS10.x.

3.3 (build 4)

Patch for ALL users with the following changes:

1) Fixed the problem that when a parameterization file (.frg) is openned, modified, and saved under a different name, the original file name was reported in the log window. Current build correctly reports the new file name as the saved file.

2) nLSI is not available anymore in the Moving Window analysis mode if the window is round due to theoretical limitations in the algorithm that is akin to trying to fit a square block in a circular hole.

3) Fixed a bug that caused the program to crash when using older .frg files.

4) Added a Search tab in the help file.

5) Fixed a bug that caused the program to crash when selecting Euclidian Nearest Neighbor patch deviation statistics in very simple landscapes (e.g., one patch per class).

6) Fixed several floating point exceptions that caused the program to crash under very specific conditions (not realized by most users).

3.3 (build 3)

Patch for ALL users with the following changes:

1) Fixes a bug in the normalized landscape shape index (nLSI) that caused FRAGSTATS to crash when the entire landscape consisted of a single patch. nLSI is reported as N/A in the output files whenever the maximum class edge equals the minimum class edge, which occurs when either the focal class consists of a single cell, all but one cell, or the entire landscape, because it impossible to distinguish among levels of aggregation in these cases. This is mainly a concern in the moving window analysis, because these conditions can be frequently encountered at relatively small window sizes as the window moves across the landscape.

3.3 (build 2)

Patch for ALL users with the following changes:

1) Fixes a problem associated with the related circumscribing circle index (CIRCLE) and contiguity index (CONTIG) when all patches have the same index value (causing a floating point error in the coefficient of variation calculation).

2) Fixes a couple of problems associated with the related circumscribing circle index (CIRCLE). First, when single-cell patches exist, CIRCLE was undefined, causing FRAGSTATS to crash. This has been fixed. Second, we also noted a problem with very small patches, say < several cells. The patch diameter is determined by finding the maximum distance between periphery cells, and this distance is used to calculate the area of the circumscribing circle. Previously, we were using cell center-to-cell center distance calculations, but this created problems for very small patches (i.e., causing negative values of the index in extreme cases). To avoid this problem, we changed the distance calculations to cell outer edge-to-outer edge. Thus, the circumscribing circle now completely circumscribes all parts of all cells in the patch and the index.

3.3 (build 1)

Update for ALL users with the following changes:

1) Includes several new metrics, including the normalized landscape shape index (nLSI), related circumscribing circle index (CIRCLE), contiguity index (CONTIG), connectance index (CONNECT), and the associated patch deviation statistics at the patch level and patch distribution summary statistics at the class and landscape levels. For the details, see the Metrics documentation.

2) Adds support for ArcGIS. FRAGSTATS will accept Arc Grids with EITHER a valid ArcGIS license OR ArcView Spatial Analyst installed. For the details, see the User Guidelines--Data Formats.

3) Adds limited command line execution of FRAGSTATS. In essence, FRAGSTATS can be called up, a parameterization file specified, and executed from a single command line. This allows FRAGSTATS to be executed from within another program. However, the parameterization file must be built using the standard FRAGSTATS graphical user interface. For the details, see the User Guidelines--Running via Command Line.

4) Incorporates a slight modification to the Shape Index (SHAPE) and Landscape Shape Index (LSI) to reflect a more accurate and meaningful way to standardize the shape index. Specifically, the minimum perimeter used to standardize the metric was adjusted to reflect the perimeter of a maximally compact patch or class in a raster format, which may not be (and typically is not) a square (which was used in the previous algorithm).

5) Corrected a bug in outputting patch ID files for ERDAS .img formats.

6) Eliminated the dependancy of the adjacency output file on the selection of the landscape-level contagion (CONTAG) metric. Now, the adjacency matrix can be output regardless of metric selection.

7) Completed an overhaul of the FRAGSTATS Help System. All FRAGSTATS documentation is now avialable from the Help Menu at the openning window of FRAGSTATS; it is no longer necessary or possible to download the Help documentation separately. However, the new HTML Help system requires the Microsoft HTML Help Viewer. Most computers with a Windows operating system have the file already, so a download will only be necessary for a slim minority of users, if any. It comes usually with Internet Explorer. If by chance you do not have the HTML Help Viewer, it is available for free at the following
as "Hhupd.exe".

8) Corrected a bug in outputting adjacency information in the adjacency file. Single-cell classes where not listed in the adjacency file. This has been corrected and now all classes, regardless of size, are reported in the adjacency file.

3.2 (build 1)


Update for ALL users with the following changes:

1) Includes all patch deviation metrics described in the Metrics documentation. These metrics provide a measure of deviation of each patch from the mean patch metric value for the corresponding class or the landscape as a whole, as well as the percentage of the patch distribution smaller than the observed patch metric value. For the details, see Metrics--Patch Metrics.

2) Adds support for 8-bit images associated with binary, ERDAS, and IDRISI files, but with some limitations. For the details, see User Guidelines--Data Formats.

3) Provides support for specifying zero as the background class value, but with some limitations. See the User Guidelines--Data Formats for the details.

4) Incorporates a slight modification to the Clumpiness Index (CLUMPY) to correct for a problem in the original formula. For the details, see Metrics--Contagion/Interspersion Metrics--Clumpy.

3.1 (build 5)


Patch for ALL users with the following changes:

1) Changes the computation of the Euclidean Nearest Neighbor (ENN) metric at the landscape level. Previously, the mean, median, range, standard deviation, and coefficient of variation in ENN at the landscape level included all patches with or without a neighbor. Patches without a neighbor (i.e., single patch classes) were incorrectly being assigned a value of zero, which of course influenced all of the patch summary statistics at the landscape level. Now, these no-neighbor patches are omitted from the calculations.

2) Fixes a problem associated with outputting patch ID files for IDRISI images. FRAGSTATS now outputs patch ID files for IDRISI images; however, the patch ID file is limited to 32,767 unique patches because IDRISI only supports 16 bit signed integers.

3) Fixes a memory leak that caused crashes during moving window analyses on very large grids with limited computer memory.

3.1 (build 4)

Patch for ALL users with the following changes:

1) Fixes another bug in the area-weighted mean disjunct core area metric (DCORE_AM) at the landscape level. This one should be correct now.

2) Fixes a number of problems with reading ERDAS files and adds support for ERDAS 8 .img files. Specifically, this build now accepts ERDAS 7 (.gis and .lan) files, although there are a number of limitations with these formats, as well as ERDAS 8 (.img) files. For the details, see User Guidelines--Data Formats for details.

3) Changes the units of the DIVISION metric from a percent to a proportion to be consistent with its interpretation as a probability.

4) Changes the comments in the Metrics document associated with the DIVISION and MESH metrics to describe their relatedness to the area-weighted mean patch size (AREA_AM) metric.

5) Fixes a bug in the browse dialog for batch files. The landscape ID field was not associated correctly with the metrics in the browse dialog box, even though they were correctly associated in the output files when saved.

3.1 (build 3)

Patch for ALL users with the following changes:

1) Introduces a new format for all secondary data files used in the calculation of certain metrics, including the edge depth file associated with core area metrics, the edge contrast weight file associated with contrast metrics, and the similarity weight file used in the similarity index. Note, this is a required patch. The older file formats will not work with this release and all subsequent releases of FRAGSTATS. For details on the new file formats, see User Guidelines--Selecting and Parameterizing Patch, Class, and Landscape Metrics.

2) Fixes a bug in the area-weighted mean disjunct core area metric (DCORE_AM).

3) Fixes a bug associated with reading ASCII and binary images containing a landscape border. Specifically, if the landscape border contained unique class IDs (i.e., patch types) NOT present in the landscape (i.e., within the landscape boundary), AND those classes did NOT touch the landscape boundary (i.e., no cell of these unique classes shared a side with cells inside the landscape), then the Contagion Index (CONTAG) and Interspersion and Juxtaposition Index (IJI) were computed incorrectly because these unique border classes were included. This bug has been fixed. In the current build, all cells in the landscape border not touching the landscape boundary are ignored in all calculations.

3.1 (build 2)
Patch for ERDAS users. Fixed bug in reading .lan and .gis image formats.
3.1 (build 1)
First release of version 3.1 software.

For more information, please contact:
Dr. Kevin McGarigal
Department of Environmental Conservation
University of Massachusetts
304 Holdsworth Natural Resources Center
Box 34210, Amherst, MA 01003
Fax: (413) 545-4358; Phone: (413) 577-0655

Copyright 2000 University of Massachusetts Amherst, Massachusetts, 01003. (413) 545-0111. This is an official page of the University of Massachusetts Amherst campus. All material in this website is made available according to the Fair Use Statute of the U.S. Copyright Act