Note for Windows users: Use wenv.bat instead of wenv.sh from the bin directory for the following examples. Also, remove the trailing backslashes in the commands and place the whole command on a single line.

Installing Weka

Using the install command, you can download and install versions of Weka. A platform-independent zip is downloaded and unzipped to a directory that you specify. Each zip file contains a directory with the Weka version, so you only need to supply a top-level directory as the installation directory.

To start with, you need to update the list of available updates (downloads a CSV file from github.com):

wenv.sh install \
  --action update

Once downloaded, you can list the versions for which we have download links:

wenv.sh install \
  --action list

This will output something like this:

Available versions:
3.6.0
...
3.7.13
3.8.0
3.8.1
3.8.2
3.9.0
3.9.1
3.9.2

Choose a version and install it in a directory, e.g., /home/fracpete/weka:

wenv.sh install \
  --action download \
  --version 3.6.10 \
  --install-dir /home/fracpete/weka

Once successfully finished, you will have the following directory containing Weka 3.6.10:

/home/fracpete/weka/weka-3-6-10

You can use this directory now for environments.

Environments

Create an environment for Weka 3.8.1:

wenv.sh create \
  --name weka381 \
  --weka /home/fracpete/programs/weka/weka-3-8-1/weka.jar

Create an environment for Weka 3.9.1 with a custom java binary to use and 4GB of heap size:

wenv.sh create \
  --name weka391 \
  --weka /home/fracpete/programs/weka/weka-3-9-1/weka.jar \
  --java /home/fracpete/programs/jdk/jdk1.8.0_144-64bit/bin/java \
  --memory 4g

Custom CLASSPATH: It is possible to inject custom jars, which will precede the weka.jar of the environment. For this, you only need to define the CLASSPATH environment variable (via --envvar) when creating (or updating) an environment.

Launching user interfaces

Launch the GUIChooser from the weka381 environment:

wenv.sh guichooser weka381

Launch the Explorer from the weka391 environment:

wenv.sh explorer weka391

Executing classes

Cross-validate J48 from the weka381 environment on the iris dataset:

wenv.sh run weka381 --class weka.classifiers.trees.J48 \
  -t /home/fracpete/development/datasets/uci/nominal/iris.arff

Aliases (global)

Create a global alias called j48:

wenv.sh alias-add --name j48 run --class weka.classifiers.trees.J48 -C 0.3

If the command of a global alias requires an environment for executing, then the environment needs to get injected via the --inject-env option. The following command executes the global alias j48, cross-validating the J48 classifier on the UCI dataset iris:

wenv.sh alias-exec --inject-env weka381 --name j48 -t iris.arff

Aliases (environment-specific)

Create an alias called j48 in the weka381 environment:

wenv.sh alias-add --env weka381 --name j48 run --class weka.classifiers.trees.J48 -C 0.3

The following command executes the alias j48 from the weka381 environment, cross-validating the J48 classifier on the UCI dataset iris:

wenv.sh alias-exec --env weka381 --name j48 -t iris.arff

Aliases (list)

You can list all aliases, global and for all environments, as follows:

wenv.sh alias-list --all

Which will output something like this:

Environment | Name | Command                                      
------------+------+----------------------------------------------
<global>    | j48  | run --class weka.classifiers.trees.J48 -C 0.3
weka381     | j48  | run -class weka.classifiers.trees.J48 -C 0.3 

You can list all global aliases as follows:

wenv.sh alias-list

You can list the aliases for environment weka381 as follows:

wenv.sh alias-list --env weka381

Environment locations

The environments get created in the following directory:

• Unix (Linux, Mac)

  $HOME/.local/share/wekavirtualenv

• Windows

  %USERPROFILE%\wekavirtualenv