How to give unique id to similar row

hi I would like to add third column to the array represents unique id for a similar rows in the array I will be grateful for any help and thank you in advance

#     30    10
#     30   191
#     30    10
#     45   206
#     30   191
#     45   206
#     45   206
#    155   206
#    155   206
#    170   191
#    155   206
#    170    11
#    170   191
#    170    11

[Birdman]

None of the rows are unique since there is at least one of them in the following rows.

[Stephen23]

@hazim78: what is your definition of "similar row" ?

[Jos (10584)]

What should the 3rd column look like?

Answer 1

[Star Strider]

I am not certain what result you want.

The unique function might be an option:

A = [30    10
     30   191
     30    10
     45   206
     30   191
     45   206
     45   206
    155   206
    155   206
    170   191
    155   206
    170    11
    170   191
    170    11];

[Au,~,ID] = unique(A, 'rows','stable');

Out = [A ID]

Out =
    30    10     1
    30   191     2
    30    10     1
    45   206     3
    30   191     2
    45   206     3
    45   206     3
   155   206     4
   155   206     4
   170   191     5
   155   206     4
   170    11     6
   170   191     5
   170    11     6

[Hazim Nasir]

thank you Star that is what I need, Id for similar rows many thanks

[Star Strider]

As always, my pleasure.