How to execute matlab program in different account user in Ubuntu

I have installed Matlab R2013b in Ubuntu system 64 bit arch. It was installed from root user. Now i can open GUI matlab and Execute programs in terminal mode, but only from root user. I cant open GUI and I cant execute programs in different user (Hadoop). I gave all permission for this user eventhough i got error. For example If i run a program like simple J=imread('/usr/a.jpg'); imwrite(J,'/usr/new.jpg'); imshow(J);

It works perfectly in root user. But in hadoop user it gives error like this

No protocol specified No protocol specified Warning: Unable to open display ':0.0'. You will not be able to display graphics on the screen. Warning: No window system found. Java option 'MWT' ignored.

                            < M A T L A B (R) >
                  Copyright 1984-2013 The MathWorks, Inc.
                    R2013b (8.2.0.701) 64-bit (glnxa64)
                              August 13, 2013

No window system found. Java option 'MWT' ignored.

To get started, type one of these: helpwin, helpdesk, or demo. For product information, visit www.mathworks.com.

{Error using imshow (line 208) IMSHOW unable to display image.

}

This is from log file. Please anyone suggest me to solve this problem. I want to execute all my commands in hadoop user only. After that I have to implement this in grid computing platform. Thanks in advance for your help. >>

[Walter Roberson]

How are you invoking MATLAB ? Which path? Are you running at a command shell or are you clicking on an icon ?

[M Prabu]

Invoked from ubuntu terminal. path is /usr/local/MATLAB/R2013b/bin. I am using matlab by command.

[M Prabu]

My question is if i change user why matlab will not work.