MATLAB: Which function should I use here to group the matrix

Question

Hello community,

Just an hour before, I asked a question, but I find out I was wrong with my interpretation and I apologise for it.

I like to ask again the modified question. I appreciate ,if you people could help me.

Here is my question.

if I have this matrix.

A = [1 0 0;

-2 0 0;

1.1 0 0;

-2.1 0 0;

1.2 0 0;

-2.2 0 0]

if i use here the sort function, I will get this

B = sort(A)

B = [-2.2 0 0;

-2.1 0 0;

2 0 0;

1 0 0;

1.1 0 0;

1.2 0 0].

and the answer I want is this,

B = [1 0 0;

1.1 0 0;

1.2 0 0;

-2 0 0;

-2.1 0 0;

-2.2 0 0].

What function should I use here? I believe this is something related to group or sorting function.

Thank you,

Answer 1

[~,ii] = sort(abs(A(:,1)));
B = A(ii,:);