[ncl-install] Fwd: GKS ERROR NUMBER -208 ?

[Octavia V. Crompton]

Hello,

I'm trying to install NCL Version 6.2.0 and testing the installation
with the command   'ng4ex gsun01n -clean'.  I'm getting the following
errors:

 GKS ERROR NUMBER -208 ISSUED FROM SUBROUTINE GOPWK :
 --X driver error: DISPLAY environment variable not set
 GKS ERROR NUMBER   25 ISSUED FROM SUBROUTINE GESC  :
 --SPECIFIED WORKSTATION IS NOT OPEN
fatal:Workstation with PID#8 is not open
fatal:Unable to open Workstation-Can't Create
fatal:Unable to access object with id:-4
fatal:_NhlCreate:Invalid Parent id #-4
fatal:NhlGetValues:PID #-4 is invalid
fatal:["Execute.c":8567]:Execute: Error occurred at or near line 12075
in file $NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl
fatal:["Execute.c":8565]:Execute: Error occurred at or near line 12
Finished running 'ncl < gsun01n'...

I have a MAC OSX, version 10.9.3.  How might I fix this?

Thanks,
Octavia