Rosetta software in 2010 MBA?

[dudulang]

Hello, everyone, I just got my MBA last week and it is my first mac. I am an informatics student and I need the Rosetta software to run some other software. I googled and everyone said Rosetta is an optional software in the Mac OS X install DVD. I checked the Reinstall Drive USB but I didn't find it.
Does anyone know how can I get this software or where can I download it please? Thank you in advance.

 

[iSee]

If it works like it did last year for me, then Mac OS will prompt you to install it when it is first used. I seem to remember the installer downloaded it, but don't quote me on that.

 

[neteng101]

Rosetta is downloaded and installed on first use.

 

[Scottsdale]

Just try to install something that needs it. OS X will prompt you to install Rosetta via Software Update.

 

[dudulang]

Thank you for your replies. I use Octave to compile matlab files. when I tried to run a "plot" function, it said:
You need the Rosetta software to run gnuplot. The Rosetta installer is in Optional Installs on your Mac OS X installation disc.

And it didn't start automatically to download the rosetta. Can you tell me which application I should run to start the auto-download?
Thank you.