- Remove support for pomp version 1. This change is the simplest way to avoid problems with CRAN checks.

- Add support for pomp version 2.

- Change name of “beta” in the parameters of the simulators to “beta_par”. This change allows the simulation code to be simplified, which both resolves an error caused by pomp version 1.19 and may prevent future errors as pomp continues to develop.

Add vaccination reaction to simulator. A vaccination rate of zero remains the default parameter setting.

Add backward-looking window option for get_stats.

Avoid errors when input time series is constant and return a missing value instead.

Add transmission argument to create_simulator to allow for frequency-dependent transmission. Density-dependent transmission remains the default model.

Add vector of first difference of the variance vector produced by get_stats. This change makes it easier to use the convexity of the variance time series as an early warning signal. The name of the vector in the stats list is variance_first_diff. Note that this change makes the abbreviation stats$var ambiguous. Code using that abbreviation to obtain the vector of variance estimates should substitute in stats$variance.

To the output of get_stats(), add list taus containing Kendall’s correlation coefficient of the elements of each time series in the stats list in the output with time.

Ensure variance and kurtosis estimates are non-negative. When using local linear for estimating statistics, it was possible in previous versions for negative values to occur.

Correct autocorrelation calculation. The previous version divided the autocovariance by the variance at the most recent time point. The current version divides by the geometric mean of the variance at each of the two time points, matching standard practice. The formula in the vignette for the autocorrelation has been changed accordingly.

Clean up sloppy usage of the term statistic in the documentation.

- Initial release