The 4.4.0 release of simmer, the Discrete-Event Simulator for R, is on CRAN. This update stabilises a new pace of a couple of new releases per year, which is more appropriate given the maturity that the project has reached.

This release brings us a dozen bug fixes and improvements, including the unification of the leave/renege API, further enhancements of convenience function to set up generators, and performance improvements for the simulation environment definition thanks to the vectorisation of add_resource and add_generator. See below for a complete list of changes.

New features

• Add out and keep_seized parameters to leave() with the same behaviour as in renege_in() and renege_if(). Code and documentation of these functions are now integrated under help(renege) (#208, #217).
• Convenience functions from, to and from_to accept dynamic parameters for arguments start_time, stop_time and every (#219).
• Activities to interact with sources have been vectorised to modify multiple sources at once (#222).
• Several generators or resources with the same parameters can be added with a single call to add_generator() and add_resource() respectively if a vector of names is provided (#221).

Minor changes and fixes:

• Fix get_mon_*() dispatch for named lists (#210).
• Get/put the RNG state when random numbers are required in the backend (#218).
• Fix convenience functions from, to and from_to to preserve the environment of the supplied functions (as part of #219).
• Documentation improvements (#212, #220).
• Fix queueing in multiple resources after preemption (#224 addressing #206).