Marx 5.0.0

Downloading and Installing Marx

Marx is distributed in the form of a compressed tar file and must be compiled before it can be used. This process is fairly painless and is something that even those who have never compiled a C program before can do. It is written in ANSI-C (with a few POSIX extensions) and is intended to be portable across most 32 and 64 bit Unix operating systems, as well as MacOSX and CYGWIN.

First download the marx tar file from ftp://space.mit.edu/pub/cxc/marx/v5.0/ and copy it to a directory that has at least a couple of hundred megabytes of free disk space. Note that this directory and its contents will no longer be needed after marx has been installed.

Next uncompress and untar the file:

    # gzip -d marx-dist-5.0.0.tar.gz
    # tar xf marx-dist-5.0.0.tar

(Some versions of tar can also uncompress the file, permitting the above to be accomplished in one step). At this point the tar file is no longer needed so it may be removed:

    # /bin/rm marx-dist-5.0.0.tar

Now change to the newly created directory to start the build process:

    # cd marx-dist-5.0.0

The next step is to run the configure script, which will probe your system to see what tools are available for compiling marx. Before doing so, it is recommended that you read the INSTALL file before proceeding.

At this point you need to think about where you want marx to be installed, and if you want the optional marxrsp program to also be created (marxrsp was written for calibration purposes--- it is not needed by most users). If you want marxrsp to be installed, then you will also need to have cfitsio compiled and installed as detailed in the INSTALL file. For simplicity, here it is assumed that marxrsp will not be installed.

Assume that you want marx installed in its own tree under /opt/marx/5.0.0/. This value is known as the installation-prefix. It is important to understand that with this choice the resulting marx executable will be placed in /opt/marx/5.0.0/bin/.

Now run the configure script specifying this value as the --prefix argument:

    # ./configure --prefix=/opt/marx/5.0.0

If all has gone well, the last bit of output from the above command should resemble:

    You are compiling MARX with the following compiler configuration:
       CC = gcc
          .
          .
       MARX parameter files will be installed in /opt/marx/5.0.0/share/marx/pfiles/.

       To continue the build process, run 'make'.

If not, then you may not have the necessary tools installed to compile marx, or you have an unsupported system. If you are unable to resolve the problem on your own, the contact marx-help at space mit edu.

Assuming all has gone well, execute the make command:

    # make

(If this step fails and you are unable to resolve the problem, then contact marx-help at space mit edu.)

The final step in the installation process is to actually install the compiled executables. If you do not have write permission to the installation-prefix directory (/opt/marx/5.0.0 in this case), then you will need to obtain the appropriate privileges to complete the next step. For example, this may require temporarily becoming the root user. Now run

    # make install

to complete the installation. As indicated above, the marx executable will be copied to /opt/marx/5.0.0/bin/. As such, it is recommended this directory be added to the user's PATH environment variable. The install step will create the following directories:

/opt/marx/5.0.0/bin/: Directory where marx, marx2fits, and other marx-related executables are placed.
/opt/marx/5.0.0/share/marx/data/: Directory under which the marx calibration data files are located.
/opt/marx/5.0.0/share/marx/pfiles/: The parameter files used by marx are located here.
/opt/marx/5.0.0/share/doc/marx/: Directory containing marx-related documentation.
/opt/marx/5.0.0/lib/: Static versions of libraries distributed with and used by marx are put here.
/opt/marx/5.0.0/include/: The C header files of the marx libraries are put here.
/opt/marx/5.0.0/lib/marx/: Contains miscellaneous marx-related tools.

As the above indicates, the marx data files will be copied to the /opt/marx/5.0.0/share/marx/data/ directory. Marx will automatically search this directory for calibration files. Also note that the parameter files will be placed under /opt/marx/5.0.0/share/marx/pfiles/. As a helpful reminder, this location is reported when marx is invoked as marx --help.

The parameter files are NOT automatically loaded by marx unless the UPARM or PFILES environment variables are set appropriately. For this reason, it is recommended that the user copy these files to the directory where the simulation will be performed.

This page was last updated Jan 24, 2012 by John E. Davis.
Technical questions should be addressed to marx-help at space mit edu.