Specify that the SYMPHONY software (Ralphs & Güzelsoy 2005) -- using the Rsymphony package -- should be used to solve a conservation planning problem(). This function can also be used to customize the behavior of the solver. It requires the Rsymphony package to be installed.

add_rsymphony_solver(
x,
gap = 0.1,

## Value

Object (i.e. ConservationProblem) with the solver added to it.

## Details

SYMPHONY is an open-source mixed integer programming solver that is part of the Computational Infrastructure for Operations Research (COIN-OR) project. The Rsymphony package provides an interface to COIN-OR and -- unlike dependencies for other solvers -- is available on CRAN. For information on the performance of different solvers, please see Schuster et al. (2020) for benchmarks comparing the run time and solution quality of different solvers when applied to different sized datasets.

## References

Ralphs TK and Güzelsoy M (2005) The SYMPHONY callable library for mixed integer programming. In The Next Wave in Computing, Optimization, and Decision Technologies (pp. 61--76). Springer, Boston, MA.

Schuster R, Hanson JO, Strimas-Mackey M, and Bennett JR (2020). Exact integer linear programming solvers outperform simulated annealing for solving conservation planning problems. PeerJ, 8: e9258.

## Examples

# \dontrun{
data(sim_pu_raster, sim_features)

# create problem
p <- problem(sim_pu_raster, sim_features) %>%