
255Stochastic or Random Processes and Time Series
> var(yrspots[,2])
[1] 1631.299
> max(acf(yrspots.rts, type=”covariance”)$acf)
[1] 1626.071
>
7.9.6 poisson process
As an example, we will use the lab7/bird-arrival.txt dataset, which contains arrival times (inaccu-
mulated hours) of birds to a site in a 12 h period starting from hour 0. The rst value is how long
it took for the rst individual to arrive, the second value is how long for the second, and so forth.
We scan the le and calculate the time difference in between successive arrivals to obtain inter-
arrival time tau. Round to three decimals, since this is the number of decimals of the values ...