Installing SSJ on Windows
SSJ requires a Java 2 Virtual Machine.
The Colt library is
used by a few SSJ classes. The library, its
source code and documentation, can be downloaded
for free from its home
page. The colt.jar archive is already included in the SSJ
distribution and it must be in the CLASSPATH environment
library is used by the class UnuranContinuous,
UnuranDiscrete, and UnuranEmpirical in the package
It can be downloaded for free from its home page.
Downloading, compiling and installing UNURAN is optional.
It is required only if SSJ must be rebuilt.
However, the UNURAN documentation is required to use
the SSJ UNURAN interface efficiently.
linear_algebra library is based on public domain LINPACK routines.
They were translated from Fortran to Java by Steve Verrill
at the USDA Forest Products Laboratory.
This software is also in the public domain and is included in the
SSJ distribution as the Blas.jar archive, which
must be in the CLASSPATH environment variable. It is used only in the
probdist package to compute maximum likelihood estimators.
The optimization package of Steve Verrill includes Java translations of the
MINPACK routines for nonlinear least squares problems as well as
UNCMIN routines for
unconstrained optimization. They were translated from Fortran to Java by
Steve Verrill and are in the public domain. They are included in the SSJ
distribution as the optimization.jar archive, which must be in the CLASSPATH
environment variable. It is used only in the probdist package to compute
maximum likelihood estimators.
By using WinZip or any equivalent program,
the user needs to
unpack the ZIP file ssj-<DATE>.zip
to any location; this will create a ssj subdirectory
containing all files of the distribution.
For example, if the files are unzipped in C:\Program
Files\java, the base directory of SSJ will be C:\Program
Set up the environment
To use SSJ, the ssj.jar, colt.jar, Blas.jar
and optimization.jar archives,
located in the lib subdirectory of the package, must be
part of the CLASSPATH
environment variable. This variable is a semicolon-separated list of
paths being searched by the Java Virtual Machine for classes.
For the native methods (Chrono and UNURAN
support) to work properly,
the PATH environment variable must include the lib
subdirectory of SSJ. This variable is a semicolon-separated list of
paths being searched by Windows when an executable or library is
Windows 95/98/Me, batch files are available to setup the environment for the
user. The SSJHOME environment must be set prior to calling the setup
Commands for Windows 9x/Me:
set SSJHOME=<path to SSJ>
Here, <path to SSJ> must be replaced by the absolute path to the
unpacked ssj subdirectory, for example C:\Program
For SSJ to be always available,
the above command lines should be added to
The computer will have to be restarted
for changes in this configuration file to take effect.
Under Windows 2000/XP, since there is no startup file,
the environment variables must be set manually.
Changes to the environment variables apply to newly-launched
programs only. As a result, if a DOS prompt was active during the
setup, it will have to be closed and reopened to access SSJ classes.
- The System Properties must be accessed by right-clicking on the
My Computer icon and selecting Properties.
- From the System Properties, the user can access the
environment variables by selecting the
Advanced tab and clicking on Environment Variables.
A user having the Administrator privilege can modify the system
variables to install SSJ for everyone on the machine while a user with a
limited account can only modify his own variables to install SSJ for himself.
- The user should create the SSJHOME variable
by using the New button
below the list of system or user variables. SSJHOME must be
entered as the variable name while the value of the variable must
be the base directory of the SSJ distribution, e.g., C:\Program
- The CLASSPATH variable must be created or modified to contain at least
If it already exists, the variable can be selected and its value can
be changed by clicking on the Edit button.
- After the PATH variable is selected, the user must click
on the Edit button to append
the string ;%SSJHOME\lib to its value.
Note on Java IDEs
Note: Some Java Integrated Development Environments (IDEs) such as
Eclipse do not use the standard
CLASSPATH environment variable.
These environments must be notified about the location of colt.jar and
ssj.jar manually. The procedure used to set these parameters can be
found in the documentation of the specific Java IDE. If the archives
cannot be located, the SSJ programs will not compile or not execute
SSJ is bundled with documentation in PDF and HTML formats. It can be
found in the %SSJHOME%\doc directory. The html
the HTML version processed using Javadoc. It allows to find classes
and methods documentation easily, but it is difficult to print and
some information is missing. It can be viewed by opening
index.html in any Web browser.
The PDF documentation, stored in the
subdirectory, can be easily printed using Adobe Reader or any other
PDF viewer. It is the most
documentation, but method descriptions are not accessible through
The examples subdirectory contains examples of simulation
using SSJ and can be a useful tool to learn SSJ.