what is the simplest way to add two vectors if size is unknown?

I would like to add v + u. I know v is 1XN but u can be 1xN or Nx1. Is it possible to do without if, and without defining a new variable, for example: w = u(:);

Answer 1

[Thorsten]

You can use the colon operator : to convert the 1XN or Nx1 vectors v and u to Nx1 and then add both

 x = v(:) + u(:);

Answer 2

[Titus Edelhofer]

Hi,

if you know that v is a row:

x = v + u(:)';

Titus

Answer 3

[Steven Lord]

 v = 1:10;
 u = v.^2;
 if rand > 0.5
  u = u.';
 end

At this point, we can't be sure of the orientation of u. Let's force u to be the same orientation as v.

 w = v + reshape(u, size(v));

[Mr M.]

sorry, i didnt describe the problem fully, in my case I would like to add: u(10:20) + v(30:40) and I dont know the size of v (coud be 1x10 or 10x1)

[Steven Lord]

There's no such thing as the 30th element of a vector with 10 elements, so with either of your v vector orientations v(30) will error.