r.maxent.setup - GRASS GIS manual

NAME

r.maxent.setup - Helper module to install Maxent to the addon directory

KEYWORDS

modeling, Maxent

SYNOPSIS

r.maxent.setup

r.maxent.setup --help

r.maxent.setup [-ju] [maxent=name] [java=name] [--help] [--verbose] [--quiet] [--ui]

Flags:

-j: Check if Java can be found on the system; Check if Java can be found from the GRASS GIS command line.
-u: Overwrites maxent.jar in addon directory; If the Maxent executable already exists in the addon directory, it will be overwritten.
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

maxent=name: Location Maxent jar file; Give the path to the Maxent executable file (maxent.jar)
java=name: Location Jave executable; Give the path to the Java executable file.

DESCRIPTION
- Maxent
- Java
NOTES
SEE ALSO
AUTHOR

DESCRIPTION

The r.maxent.setup addon provides a helper function to install Maxent and ensures that GRASS GIS can locate the Java executable, a prerequisite for running Maxent.

The r.maxent.train and r.maxent.predict modules require the Maxent software, which can be downloaded from the Maxent website. The r.maxent.setup installs this to the GRASS GIS addon directory. If you want to update the Maxent.jar file, use the -u flag.

Java

Maxent requires Java to be installed, and it should be accessible from the GRASS GIS environment. You can check this by running the r.maxent.setup with the -j flag.

On Windows, even if JAVA is installed and on the PATH, GRASS GIS may still not be able to find it. The reason is that OSGeo4W environment used by GRASS GIS on Windows has its own shell environment, which may not automatically inherit the system-wide PATH or environment variables from Windows. As a result, even if Java is correctly installed and accessible from a regular Command Prompt or PowerShell, it might not be visible to GRASS GIS within the OSGeo4W shell.

To enable GRASS GIS to find the path to the Java executable, you can set the path to the executable using the java parameter. The path will be written to a text file in the GRASS GIS addon directory, which can be used by the r.maxent.train and r.maxent.predict modules.

An arguably better but more involved way is to add the Java directory to the OSGeo4W PATH. See the NOTES for a short 'how to'.

NOTES

Instead of using this addon to set the path to the java executable, you can add the Java directory to the OSGeo4W PATH temporarily. Open the Open the OSGeo4W shell and run the following:

set PATH=C:\Program Files\Java\jdk-XX.X.X\bin;%PATH%

Replace C:\Program Files\Java\jdk-XX.X.X\bin with your Java installation path. To make this change persistent, you need to edit the osgeo4w.bat file. This file can be found in the OSGeo4W installation folder. Locate the file, and find the line that starts with set PATH=.

At the end of that line, add a semi-colun and the path to the Java installation path. For example:

set PATH=%PATH%;C:\Program Files\Java\jdk-XX.X.X\bin;

Replace C:\Program Files\Java\jdk-XX.X.X\bin with your Java installation path. Save the file and restart the OSGeo4W shell. Note that you may need administrator rightrs to edit the osgeo4w.bat file.