Section: Mathematical Functions
y = mod(x,n)
where x is matrix, and n is the base of the modulus.  The
effect of the mod operator is to add or subtract multiples of n
to the vector x so that each element x_i is between 0 and n
(strictly).  Note that n does not have to be an integer.  Also,
n can either be a scalar (same base for all elements of x), or a
vector (different base for each element of x).
Note that the following are defined behaviors:
mod(x,0) = x@
 mod(x,x) = 0@
 mod(x,n)@ has the same sign as n for all other cases.
 mod
arrays.
--> mod(18,12) ans = 6 --> mod(6,5) ans = 1 --> mod(2*pi,pi) ans = 0
Here is an example of using mod to determine if integers are even
 or odd:
--> mod([1,3,5,2],2) ans = 1 1 1 0
Here we use the second form of mod, with each element using a 
separate base.
--> mod([9 3 2 0],[1 0 2 2]) ans = 0 3 0 0