Mac Grapher Complex Error Function I understand the the Grapher app in Mac OS X comes with erf and erfc, the error function and complementary error function. However, when I define

y = Re[erfc(-ix)],


the Grapher app just returns y(x) = 0 for all values of x. Is it not possible to give this function complex values?
You may well find that somewhere in there the complex number is being flattened and you will need to use the complex() function to protect it from that.

Check this out :- 

http://acko.net/blog/taming-complex-numbers-in-grapher-app/