Simple set of examples for creating simulated data for random walkers and then using either the mean squared displacement (MSD) or fitting the expected probability distribution function (PDF) to the positions in the last time step. There is then an example of how to use this for a hypothetical exmperiment. I made these to help a student who was investigating Brownian motion of pollen grains using image tracking determine the diffusion coefficient as a function of various parameters e.g. temperature, viscosity, grain size etc.