Solve a Pyomo model exported by multimod — solve

Executes the generated solve.py script inside solvers/pyomo/ after ensuring a Python environment exists. By default the helper setup_python_environment() is invoked so that a Conda environment named "multimod" (configurable) is created, populated with Pyomo, and activated via the reticulate toolkit. Once the environment is ready the solver script is executed with system2() or processx and basic status information is returned. Result loading is not implemented yet but the metadata emitted by solve.py (e.g. solution/status.json) is surfaced when available.

Usage

solve_pyomo(
  model = NULL,
  model_dir,
  solver_dir = "pyomo",
  env_name = "multimod",
  ensure_env = TRUE,
  packages = c("pyomo"),
  python_version = NULL,
  ensure_miniconda = TRUE,
  reinstall_env = FALSE,
  python = NULL,
  solver = NULL,
  env = NULL,
  load_results = FALSE,
  verbose = c("buffer", "stream", "quiet"),
  timeout = NULL,
  ...
)

Arguments

model: Optional multimod model; currently only used when load_results = TRUE to indicate where solutions should be loaded (not yet implemented).
model_dir: Path to the saved model directory created by save_model(). Must contain solvers/<solver_dir>/solve.py (generated via write_pyomo()).
solver_dir: Name of the solver sub-directory inside model_dir/solvers. Defaults to "pyomo" to match write_pyomo().
env_name: Name of the Conda environment handled by setup_python_environment(). Defaults to "multimod".
ensure_env: Logical; when TRUE (default) the helper setup_python_environment() runs to create/activate the environment. Set to FALSE if you want to manage activation yourself.
packages: Character vector of Python packages to request when the helper runs. Defaults to "pyomo".
python_version: Optional Python version passed through to setup_python_environment().
ensure_miniconda: Forwarded to setup_python_environment().
reinstall_env: When TRUE, asks the helper to recreate the Conda environment before solving.
python: Optional path to a Python executable. When omitted the Python binary reported by reticulate::py_config() for the activated environment is used.
solver: Optional solver name that is exported to the Python process via the PYOMO_SOLVER environment variable.
env: Named character vector of additional environment variables to pass to the Python process.
load_results: Logical; reserved for future work. When TRUE a warning is issued because loading solutions back into R is not yet implemented.
verbose: Controls solver logging capture. Logical (TRUE = buffer output, FALSE = quiet) or one of "buffer", "stream", "quiet".
timeout: Optional timeout (in seconds). Requires the processx package.
...: Additional arguments forwarded to setup_python_environment().

Value

A list describing the solver run (exit code, success flag, elapsed time, raw output, parsed status metadata when available, and environment details).