Matlab modulo specific behaviour

Question

I have the following problem. Let\'s say I have four possible values {1 2 3 4} and I want a specific behavior of mod function

The behavior I seek is th

Answer 1

How about:

function [result] = my_mod(x,y)
m = mod(x,y);
result = m+~m*y;

The ~ negates the result from mod, i.e. :

• ~0 == 1
• ~1 == 0
• ~2 == 0
• ...

So we only add y if the result from mod is 0.

demo

>> my_mod(1:8, 4)

ans =

 1     2     3     4     1     2     3     4

Answer 2

If A holds those values, you can subtract 1, perform mod and add back 1.

Sample run -

>> A = 1:8
A =
     1     2     3     4     5     6     7     8
>> mod(A-1,4)+1
ans =
     1     2     3     4     1     2     3     4