HEEELP!!!!

Hello

 When copying the script in the R console, it seems that there is a problem
 with the

 ~ symbol. this symbol is not in the keyboard, so I select it from spetial
 characters,

For what language is your keyboard designed? If it is for English,
similar to this one [1], try a British English layout, and then the ~
sign will (possibly) be on the "\" button (press shift+\). I'm on
Linux, but I hope it would be similar for Mac.
Liviu

[1] http://www.mrtotes.co.uk/UK_Mac_Keyboard.jpg