Ifarm graphic mode

Usually we are running code on ifarm without caring about graphic because it's used for a test ground for farm job anyway.

Sometimes we do want to test a code's graphic feature. For example, it's a common system we all have access and can be used for debug.

One way to do it is simply "ssh -X" or "ssh -Y" into ifarm and run the code. but the problem is that Xwindow graphic is always rendered in your local machine. So not only the test can have different results for different people because their local machines are different. Sometimes, it can cause crash of your local machine if your code is not nice and your local machine is very different from ifarm.

The better way to do it is through a vnc inside ifarm. This way the code won't crash because it runs within the same environment where it is compiled and everyone will see same result. Here is how to do it

ssh -X jlab_user_name@ifarm         (try "-Y" if "-X" doesn't work)
xclock