Installing MATLAB on Linux

Notes:

1. These instructions have been tested for MATLAB R2011a on Lubuntu 11.10.
2. For more details, refer to install_guide.pdf in MATLAB setup ISO/folder. You can get this file (and complete official MATLAB documentation) for free (just create a free MathWorks account) at:
   
   • Installation documentation (for latest version of MATLAB)
   • Printable PDF documentation (for latest version of MATLAB)
   • Documentation for older releases

I followed these steps to install MATLAB on Lubuntu Linux:

1. Extract or mount the MATLAB ISO file. Let's assume that you extracted MATLAB ISO file to

   /home/user/matlab

2. Change to the extracted directory and run:
   

   cd /home/user/matlab
   sudo ./install

3. When I ran above command, I got this error message (and installer exited without completing the install):
   

   user@system:~/matlab$ sudo ./install 
   [sudo] password for user: 
   Preparing installation files ...
   Installing ...
   eval: 1: /tmp/mathworks_2463/java/jre/glnx86/jre/bin/java: Permission denied
   Finished
   user@system:~/matlab$

   MathWorks India has a solution page to this problem. It lists the cause of problem and a solution. But this solution is better (imho) and worked very well for me! All you need to do is run following command on terminal/console:
   
   • For Linux (32-bit):
     

     chmod ugo+x /home/user/matlab/java/jre/glnx86/jre/bin/java

   • For Linux (64-bit):
     

     chmod ugo+x /home/user/matlab/java/jre/glnxa64/jre/bin/java

   Google has loads of related stuff if you search for "matlab java Permission denied".
4. Don't start MATLAB after installation. Run these commands on terminal [1]:
   

   mkdir ~/.matlab
   sudo chown -R ${USER}:${USER} ~/.matlab

5. MATLAB got installed (by default) to /usr/local/MATLAB. To run matlab use:
   

   /usr/local/MATLAB/R2011a/bin/matlab

[1] http://thameera.wordpress.com/2010/10/21/installing-matlab-2008a-on-ubuntu-10-10/

Decompressing .ZIPX on Unix-like systems

Any new technology tends to go through a 25-year adoption cycle.
-- Marc Andreessen

Newer versions of WinZip introduced the extension .zipx for the ZIP files that use newer compression methods. Many commercial programs offer support for .zipx files but if you want a free and open source program to handle .zipx (especially to decompress .zipx files), you can use 7zip (http://www.7-zip.org/). 7-zip added support for .zipx files in version 9.18.

On Windows, any installer with version >9.18 will do the trick.

On Unix-like systems, there are few possibilities to install and use 7zip (mind you, only 7zip versions >9.18 support .zipx format):

• Find a 7zip package for your distribution's package manager (or, compile 7zip yourself).

• Or, you can install and use 7zip in wine (http://www.winehq.org/).

• Or, use p7zip POSIX/Linux x86 binary (http://sourceforge.net/projects/p7zip/files/p7zip/)

That's it!

Assigning keyboard shortcut to easily switch between keyboard layouts

Never memorize something that you can look up. -- Albert Einstein

Lubuntu 11.04 has a tool called lxkeymap to easily switch to another keyboard layout , but there was no way to assign a keyboard shortcut to switch back and forth between two or more keyboard layouts using lxkeymap.

'phillw' on #lubuntu (irc.freenode.net) pointed me to this post on ubuntu forums.

To switch between 'standard' QWERTY and DVORAK layouts:
setxkbmap -option grp:alt_shift_toggle us,dvorak
This assigns ALT+SHIFT keyboard shortcut to switching layout between QWERTY and DVORAK.

Error in virtualbox: "No suitable vboxnetflt module for running kernel found"

If you get this error during boot on console:
"No suitable vboxnetflt module for running kernel found"
and you are unable to run any virtual machines inside virtualbox, then you are missing the linux kernel required to run this version of virtualbox.

This log (from debian lenny) provides some useful information (Lines 90, 91, 92, 108, 109, 110 are worth noting):
http://codepad.org/twhonwWA

So, find out the version of linux kernel you need and install it using your package manager.

Thanks to folks at #debian, #vbox (at freenode) for help. 

Editing PDFs on Unix/BSD/Linux

Computers make it easier to do a lot of things, but most of the things they make it easier to do don't need to be done. -- Andy Rooney

Programs in the list that follows are free (at least for non-commerical use) at the time of writing.

1. PDFedit
http://pdfedit.petricek.net/en/index.html

2. flpsed
http://flpsed.org/flpsed.html

3. Xournal
http://xournal.sourceforge.net/

4. Jarnal
http://www.dklevine.com/general/software/tc1000/jarnal.htm

5. PDF-Xchange viewer (Use Wine to run this program under *nix.)
http://www.docu-track.com/home/prod_user/pdfx_viewer/

Note: Alternatively, there are many online PDF editors available. You know how to use Google...right? 

If I find other similar applications, I'll append them to this post.