Changes in version 0.4.0 (2026-03-11)                  

  - Requires R (>= 4.1.0).
  - Internal optimizations to reduce runtime.

                 Changes in version 0.3.0 (2023-10-23)                  

  - Rewrote config(), breaking the components of a config object out
    into a hierarchy of (new) S3 objects: predictors, life_cycle,
    parameters, predictor_spec, transition_function, and transition.
    This has numerous advantages, including the ability for users to
    build up individual components of a config with validation from the
    new classes, rather than constructing the entire config object in
    one step. This update means users need to modify any existing config
    objects to fit the new schema. The most significant changes are:
      - Life cycles are represented with the life_cycle class, which
        contains a list of transition objects. Previously, this data was
        represented in the transitions and parameters attributes of a
        config.
      - Modified the mechanism for passing functions to transitions to
        compute transition probability or duration. These functions are
        now wrapped in a class, transition_function. Previously, configs
        contained strings with the name of functions to get() from the
        environment; now we pass the transition_functions themselves.
        This removes the model's dependence on the global R environment,
        improving reproducibility.
      - Using predictor_spec and parameters, passing parameter and
        predictor values to transition_functions is now done more
        explicitly.
  - Updated the example configs to conform to the new schema.
  - Removed several pieces of non-core functionality that we think are
    better handled by users. This refocuses the package on its core
    purpose: configuring and running tick population models.
      - Removed read_config() and write_config(), which provided the
        ability to serialize and deserialize configs. These functions
        were not sufficient to comprehensively serialize all configs for
        reproducible model results. Now, the package only handles
        in-memory objects.
      - Removed run_all_configs() and the related parallel package
        dependency. This function was just a thin wrapper over a call to
        lapply or a parallel apply operation.
      - Removed graph_lifecycle() for visualizing the flow between life
        stages, and the dependency on the package igraph. Instead,
        life_cycle includes a print method with useful information on
        the flow between life stages.
      - Removed vary_param() and vary_many_params().
      - Removed the graphing functions graph_population_each_group() and
        graph_population_overall_trend(). These functions were intended
        as an easy way to visualize model results, but they did not
        handle all cases, since model output can be highly variable. We
        now recommend users write their own code, e.g. with ggplot2, to
        visualize results.
  - Removed three columns from the data frame output from run():
    age_group, process and infected. These columns were populated based
    on the assumption that life stage names were structured as a
    three-character string like <process><infected><age_group>, and used
    downstream in the graphing functions. Now, users are completely free
    to name life stages as they wish.
  - Added annual_growth_rate(), for determining the annual factor by
    which population changes. Results from the growth_rate() function
    can be sensitive to the specific time period being modeled -- this
    aims to be a more universally applicable alternative.
  - Refactored growth_rate() to use base R.

                 Changes in version 0.2.0 (2022-02-08)                  

  - Added new configs to the package.
      - ogden2005, which replicates an existing deer tick population
        model by Ogden et al. (2005).
      - winter_tick, based on literature on the winter tick and used as
        an example of the package's flexibility for studying different
        tick species.
      - host_example_config, infect_example_config, and
        temp_example_config, which are used as examples of package use.
        Added examples with these configs to the readme.
  - Generalized config() to take a single predictors argument, instead
    of separate weather and host_comm arguments. This simplifies the
    config() structure, and allows using other types of data as a
    predictor for transitions.
      - write_config() arguments are updated to reflect this change.
      - Some internal functions are updated to support this change.
  - Added snow_cover_fun() transition function which is used in the
    winter_tick model configuration.
  - Fixed write_config() to write steps and initial population as
    integers rather than decimal numbers.

                 Changes in version 0.1.0 (2021-11-08)                  

  - First launch of IxPopDyMod package