Finally solving the export installation issue ... totally the fault of rJava

[hammao]

After wasting a full day reinstalling r, studio, java and so on... I stumbled on this two webpages that totally fixed my problem.... they are easy to follow an will solve your problem in 5 mins

1. http://www.snaq.net/software/rjava-macos.php, for directing R to your java installation folder you can skip all the detailed explanation ( very useful though) and go straight to the "Quick version" I configuration section.
2. https://stackoverflow.com/questions/47658210/loading-rjava-on-mac-os-high-sierra?rq=1 for installing rJava from source via terminal.