Assigning matrix rows to the same value and plotting

Hi! So I'm relatively new to coding, so I'm sure there is a simple answer for this. Anyways, here is my problem:

I have a matrix, say x = [1 2 3;4 5 6;7 8 9], and each row corresponds to a different value, say u = -3,0,3. I'm trying to generate a plot like (-3, [1 2 3]), (0,[4 5 6]), (3, [7 8 9]). But I'm having some trouble.

My idea was to generate a matrix of two columns using the following code:

plot_data = [];
for i=1:length(u)
    for m = 1:length(x)
        x1 = u(i)
        y1 = x(i,m)
        plot_data(m ,1) = x1
        plot_data(m ,2) = y1
    end
end

I'm sure I'm doing this in a very roundabout way, and the code I wrote doesn't work correctly. Can anyone give me some help?

[Image Analyst]

I don't know what "a plot like (-3, [1 2 3]), (0,[4 5 6]), (3, [7 8 9])" looks like. Mock up something in Photoshop, or draw something and take a photo or it or scan it in, and post a picture of it.

Answer 1

[Walter Roberson]

   x = [1 2 3;4 5 6;7 8 9];
   u = [-3,0,3];

   y = repmat(u(:), 1, size(x,2));

plot(x.', y.')
ylim([min(u)-1, max(u)+1])

[Aaron]

Thanks Walter! Works perfectly :D