MOD Modulus Operation

Section: Mathematical Functions

Usage

Computes the modulus of an array. The syntax for its use is
   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:

  1. mod(x,0) = x@
  2. mod(x,x) = 0@
  3. mod(x,n)@ has the same sign as n for all other cases.

Example

The following examples show some uses of mod arrays.
--> mod(18,12)
ans = 
  <double>  - size: [1 1]
 6  
--> mod(6,5)
ans = 
  <double>  - size: [1 1]
 1  
--> mod(2*pi,pi)
ans = 
  <double>  - size: [1 1]
 0  

Here is an example of using mod to determine if integers are even or odd:

--> mod([1,3,5,2],2)
ans = 
  <double>  - size: [1 4]
 
Columns 1 to 4
 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 = 
  <double>  - size: [1 4]
 
Columns 1 to 4
 0  3  0  0