Can I set the primary Language of OS X by using shell script or AppleScript?

My computer is mac mini (late 2012) with Yosemite 10.10.1 installed. The primary language of the system is English, with Chinese being the second language.

Sometimes I need to use the Maps.app, and as a Chinese person, a map with Chinese characters is more comfortable for me to use rather than English. So when I use the Maps.app, I have to temporally switch the primary language into Chinese, and then switch back to English after using the Maps.

But, it's really inconvenient to do the switchings all by clicking the Settings icon, clicking the Language item, and dragging the language up and down.

Can I do these actions by writing scripts, such as AppleScript or shell script? Thank you very much!

P.S. I've checked the dictionaries of AppleScript and also the OS X manual pages, but found nothing help. It seems that no such 'language setting command' exists.