Can I replace the row of the matrix when its value is equal to the previous row?

Hello,

I have a following matrix as a sample/

A = [1 2 3; 4 5 6; 1 2 3; 1 2 3];

And I would like to replace the value of entire row if the row is equal to the previous row.

So in this case,

B = [1 2 3; 4 5 6; 1 2 3; 0 0 0]

Because the last row is equal to the 3rd row of the matrix.

Is there anyway I could do this?

Thank you.

Answer 1

[Atsushi Ueno]

A = [1 2 3; 4 5 6; 1 2 3; 1 2 3]

A = 4×3

1 2 3 4 5 6 1 2 3 1 2 3

diff(A,1)

ans = 3×3

3 3 3 -3 -3 -3 0 0 0

replace_row = [false; ~all(diff(A,1),2)]

replace_row = 4×1 logical array
   0
   0
   0
   1

A(replace_row, :) = 0

A = 4×3

1 2 3 4 5 6 1 2 3 0 0 0