poems - Pattern-Oriented Ensemble Modeling System
A framework of interoperable R6 classes (Chang, 2020,
<https://CRAN.R-project.org/package=R6>) for building ensembles
of viable models via the pattern-oriented modeling (POM)
approach (Grimm et al.,2005, <doi:10.1126/science.1116681>).
The package includes classes for encapsulating and generating
model parameters, and managing the POM workflow. The workflow
includes: model setup; generating model parameters via Latin
hyper-cube sampling (Iman & Conover, 1980,
<doi:10.1080/03610928008827996>); running multiple sampled
model simulations; collating summary results; and validating
and selecting an ensemble of models that best match known
patterns. By default, model validation and selection utilizes
an approximate Bayesian computation (ABC) approach (Beaumont et
al., 2002, <doi:10.1093/genetics/162.4.2025>), although
alternative user-defined functionality could be employed. The
package includes a spatially explicit demographic population
model simulation engine, which incorporates default
functionality for density dependence, correlated environmental
stochasticity, stage-based transitions, and distance-based
dispersal. The user may customize the simulator by defining
functionality for translocations, harvesting, mortality, and
other processes, as well as defining the sequence order for the
simulator processes. The framework could also be adapted for
use with other model simulators by utilizing its extendable
(inheritable) base classes.
