Particle-Takens Stability R package pttstability version 1.4 Includes a collection of functions presented in "Measuring stability in ecological systems without static equilibria" by Clark et al. (2022) <doi:10.1002/ecs2.4328> in Ecosphere. These can be used to estimate the parameters of a stochastic state space model (i.e. a model where a time series is observed with error). The goal of this package is to estimate the variability around a deterministic process, both in terms of observation error - i.e. variability due to imperfect observations that does not influence system state - and in terms of process noise - i.e. stochastic variation in the actual state of the process. Unlike classical methods for estimating variability, this package does not necessarily assume that the deterministic state is fixed (i.e. a fixed-point equilibrium), meaning that variability around a dynamic trajectory can be estimated (e.g. stochastic fluctuations during predator-prey dynamics). Software Depends: R (>= 3.4) Imports: graphics, stats Suggests: BayesianTools Adam Clark <adam.tclark@gmail.com> Comprehensive R Archive Network (CRAN) Adam Clark [aut, cre] (ORCID: <https://orcid.org/0000-0002-8843-3278>) GPL-3 2024-01-09 application/tgz https://CRAN.R-project.org/package=pttstability doi:10.32614/CRAN.package.pttstability