MATLAB: How to swap elements of the first column of the S matrix with the first line elements

Question

Hi I have a matrix

A=[1 2 3;
   4 5 6;
   7 8 9]

but I want to switch the first column with first line like this

A=[1 4 7;
   2 5 6;
   3 8 9].

What it's the fast way to do it? Any help is appreciated! Thank you

Answer 1

If only the 1st column and row are involved, e.g. a simple swap:

A1 = A(:,1);
A(:,1) = A(1,:);
A(1,:) = A1;