how to delete same cols from a matrix

for example, a=[4 5 6 5 6 4; 4 6 5 3 5 4; 4 7 2 8 2 4; 4 2 4 7 4 4; 4 3 9 1 9 4;] is.

so, row=1 & 5 and row =2 & 4 is same.

what i want is to delete same row. but each ones must remain.

Answer 1

[KSSV]

doc unique

   b = unique(a', 'rows')'