The grid spacing is 
and 
in the x and z direction, respectively.
The number of time steps are 
and the computational effort is 
,
or floating point operations per step.
The number of individual shot records is 
.
The n terms are about the same magnitude and 
is considerably less
in value, typically around 25;
is the operations count of
the finite difference operator.
The complexity of
shot record modeling is 
and the
complexity of zero-offset modeling is
which is 
less.
