MATLAB: How to detect repeated values between rows

Question

Hi I have

 a=   1     2
      3     1
      2     3
      2     3
      3     2
      1     1

I want to detect whether this matrix has repeated elements between rows or not. The condition is, the row must be subsequent to each other. Obviously, 3rd and 4th rows have same elements, hence display 'hello'. For another example,

 b=  1     2
     2     3
     3     1
     2     3
     3     2
     1     1

'b' have repeated elements in 2nd and 4th rows, but it does not fulfill the condition that the row is subsequent to another row. Hence, 'hello' will not be displayed.

How am I going to do this? Thank you.

Answer 1

You can use the diff function:

if any(sum(abs(diff(a,1)),2)==0)
msgbox('hello')
end