function msd_t = msd_ind(xcoors,ycoors,particle_num,timestep,base)
% This function returns the mean square displacement for a single particle
% at a certain timestep, with reference to certain base value.

% It follows the formula: (1/N)(SUM_TO_N((r(i,t) - r(i,base))^2)) but
% because N = 1 (because we are using only one individual particle), we
% remove the SUM and (1/N). Splitting r into it's x and y parts gives msd =
% change_in_x^2 + change_in_y^2.
    cx = xcoors(particle_num,timestep+1) - xcoors(particle_num,base);
    cy = ycoors(particle_num,timestep+1) - ycoors(particle_num,base);
    msd_t = cx^2 + cy^2;