1. An analysis device comprising: a substitution unit for substituting each event in an impulse-like event series with rectangular pulses; a dividing unit for dividing the event series so as that at least one element of the rectangular windows varies at every splitting timestamp; a state vector generation unit for generating a state vector corresponding to the state of the rectangular windows in response to each of the divided time periods; and an analysis unit for performing Poisson regression using the state vectors corresponding to the time periods.