.PP
Both programs have two user interfaces, a command line user interface and an
interactive user interface.  If the user specifies any command line options, the
programs use the command line user interface.  Otherwise, they prompt the user
for the required parameters via the interactive user interface.  The interactive
interface is generally easier to use, but the command line interface
has the advantage that the program invocations can be put in shell scripts for
batch execution and easy modification.  Use of the interactive interface
should intuitive after reading the OPTIONS section below.  Both user interfaces
have the same defaults.  Every option has a default except for the surface 
specification; 

