msdanalyzer：用于均方位移分析的MATLAB类

MSD analyzer ============ Mean square displacement (MSD) analysis is a technique commonly used in colloidal studies and biophysics to determine what is the mode of displacement of particles followed over time. In particular, it can help determine whether the particle is: * freely diffusing; * transported; * bound and limited in its movement. On top of this, it can also derive an estimate of the parameters of the movement, such as the diffusion coefficient. @msdanalyzer is a MATLAB per-value class that helps performing this kind of analysis. The user provides several trajectories he measured, and the class can derive meaningful quantities for the determination of the movement modality, assuming that all particles follow the same movement model and sample the same environment.