Plotting random vectors

Just a heads up, I have virtually no matlab experience. I need to generate a an XY-plane where a random number 'n' vectors will be plotted. How do I do this?

Also, after they are plotted I want to iterate the function so that every time I hit enter the graph will update moving the vectors in a certain manner based on the following two functions: (x_i is the i^th particle's position) x_i(t + 1) = x_i(t) + v_i(t)(t-t_0) as position

(i^th particles direction) theta(t+1) = theta(t)_r

where theta(t)_r denotes the average direction of velocities of of the particles surrounding the ith particle being within a circle of radius r.

Hopefully this would eventually make all the vectors point in the same direction and cluster to a certain area.

Thanks in advance

Answer 1

[Poul Reitzel]

R = rand(N) returns an N-by-N matrix containing pseudorandom values drawn from the standard uniform distribution on the open interval(0,1).

You could draw your vectors from R by random coordinates for every vector. For plotting consider using the file:

http://www.mathworks.com/matlabcentral/fileexchange/7470

If you need to update the plot, put a 'hold on' command after plotting the initially generated vectors. Then update the coordinates based on the requirement you mention. In a loop I would see this simple solution working.

I hope it helps!

Best regards, Poul Reitzel

[Jenn Lee]

Oh wow! Thanks!

In the second part of your answer you mentioned that I could draw my vectors from R by making random coordinates. How would I make random coordinates for every vector though?

[Jenn Lee]

If I use R = rand(n), can I use quiver() to generate vectors for the points? And would I just use plot(R) to graph the generated points of R?