Copy a row or column of a matrix and insert it in the next row/column

Question

I was wondering if there is an easy way in MATLAB to do the following operation: I'd like to copy a row or column of a matrix and insert it in the next row/column.

For example: given a 3x3 matrix

1 2 3
4 5 6
7 8 9

I'd like to copy the first row and insert it as a second row:

1 2 3
1 2 3
4 5 6
7 8 9

Can someone advise how I could accomplish this in MATLAB? Thanks!

Answer 1

You can simply repeat the indices of the rows you'd like to repeat

A = A([1 1 2 3],:)

Answer 2

To insert row number source as row number target:

A = [A(1:target-1,:); A(source,:); A(target:end,:)];