Michael McCourt : mccomic@mcs.anl.gov (or mccomic@iit.edu)
Office : E1 105d
Office Hours : MW 10:00-1:00, TR 2:00-5:00
X Forwarding
PETSc, and Matlab, provide you the opportunity to work with a graphical
interface at times. Most of you always access Matlab through the
graphical interface, whereas PETSc only provides graphics occasionally.
Specifically, when you are trying to plot the sparisty structure of a
matrix or review the convergence of a SNES iteration, PETSc provides
this graphically.
Unfortunately, it is not trivial to send graphical information over a
network, and as a result it is necessary for you to provide the server
with a way to talk to your computer. This is called X forwarding,
because you are trying to open a X11 window on your computer. There are
multiple ways to handle this depending on what your OS is.
UNIX X Forwarding
For those of you running a UNIX operating system to access the
ada.cs.iit.edu server, you likely use a command similar to
ssh -l #userid# ada.cs.iit.edu
To activate X forwarding all you need to do is pass one additional
parameter:
ssh -X -l #userid# ada.cs.iit.edu
That's it, because UNIX automatically has an X server running on it.
Windows X Forwarding
If you are running Windows as your operating system, the situation is
not as simple. Unfortunately Windows does not provide an X server
natively, which means that you need to install one. This is not a
problem if you are running on your own machine, but if you are running
on a public machine you may not be allowed to install programs easily.
Assuming that you are allowed to install the X forwarding client, at
least in your own personal directory, you need to choose one to use.
The most common choice is xming and it is very
small and easy to install. If you do not have it yet, feel free to
Once the installation is finished, you now
need to change a couple things with your PuTTY options.
Start up the PuTTY gui and set it up as though you were about to log in
to ada.cs.iit.edu. Before you log in, go to the configuration section
on the left and open Connection>SSH>X11. Check the Enable X11
forwarding box and under X display location type
'localhost:0' without the quotes.
Now when you start up your session you should be able to do X
forwarding.
