[lastposition] function = brownian(steps) %BROWNIAN - A function that simulates Brownian motion of a particle. %input - number of steps in simulation, must be an integer. %output - a plot of the particles motion in the x-y plane. %call - call from the command window, e.g. brownian(10000) position = [0 0]; %initial position origin at x = position; %pos vec x;col 1 x; col 2 y for k = 1:steps; %for loop theta = 2*pi*rand; %0 < random direction <2*pi position = x(end,:)+[cos(theta) sin(theta)];%polar to cart; new pos x = [x;position]; %add new pos to vector x end plot(x(:,1),x(:,2),'-k'); lastposition = [x(end,1),x(end,2)]; end