How to add values around a vector without changing the vector values.

So I am trying to take a vector y = (19,1) that I am solving for the values of change that into a vector y = (21,1).

I want the values in rows 1 and 21 to be 0 with the solved for values remaining in rows 2 thru 20.

Answer 1

[VBBV]

%if true
Y = 1:21;
Y = Y'
Y(1,1) = 0; Y(21,1) = 0

[Travis Gardner]

The problem with this is I am starting with a vector of 19 rows because my matrix is a 19 x 19. Doing this changes the entire solved vector. The last line of code should work perfectly, but I need to change from a 19 row to a 21 row, shift row 1 to 2 and so on, then make row 1 and 21 into 0.