i2extras adds additional functionality to the incidence2 package.

What does it do?

The main features of the package include:

  • fit_curve() and growth_rate(): fit a trend (poisson / negative binomial) to an incidence2 object and calculate the associated growth rate.

  • add_rolling_average(): add a rolling average to an incidence2 object.

  • bootstrap(): generates a bootstrapped incidence2 object by re-sampling, with replacement, the original dates of events.

  • find_peak(): locates the peak time of the epicurve.

  • estimate_peak(): uses bootstrap to estimate the peak time (and related confidence interval) of a partially observed outbreak.

Installing the package

Once it is released on CRAN, you will be able to install the stable version of the package with:


The development version can be installed from GitHub with:

if (!require(remotes)) {
remotes::install_github("reconverse/i2extras", build_vignettes = TRUE)



An overview of i2extras is provided in the included vignettes:

Getting help online

Bug reports and feature requests should be posted on github using the issue system. All other questions should be posted on the RECON slack channel see https://www.repidemicsconsortium.org/forum/ for details on how to join.