Add proportion decisions
Add a proportion decision to a conservation planning problem().
This is a relaxed decision where a part of a planning unit can be
prioritized as opposed to the entire planning unit. Typically, this decision
has the assumed action of buying a fraction of a planning unit to include in
decisions will solve much faster than problems that use binary-type
decisions
add_proportion_decisions(x)
x |
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Conservation planning problems involve making decisions on planning
units. These decisions are then associated with actions (e.g. turning a
planning unit into a protected area). If no decision is explicitly added to
a problem, then the binary decision class will be used by default. Only a
single decision should be added to a ConservationProblem object.
Note that if multiple decisions are added to a problem object, then the
last one to be added will be used.
Object (i.e. ConservationProblem) with the decisions added
to it.
# set seed for reproducibility
set.seed(500)
# load data
data(sim_pu_raster, sim_features, sim_pu_zones_stack, sim_features_zones)
# create minimal problem with proportion decisions
p1 <- problem(sim_pu_raster, sim_features) %>%
add_min_set_objective() %>%
add_relative_targets(0.1) %>%
add_proportion_decisions() %>%
add_default_solver(verbose = FALSE)
## Not run:
# solve problem
s1 <- solve(p1)
# plot solutions
plot(s1, main = "solution")
## End(Not run)
# build multi-zone conservation problem with proportion decisions
p2 <- problem(sim_pu_zones_stack, sim_features_zones) %>%
add_min_set_objective() %>%
add_relative_targets(matrix(runif(15, 0.1, 0.2), nrow = 5,
ncol = 3)) %>%
add_proportion_decisions() %>%
add_default_solver(verbose = FALSE)
## Not run:
# solve the problem
s2 <- solve(p2)
# print solution
print(s2)
# plot solution
# panels show the proportion of each planning unit allocated to each zone
plot(s2, axes = FALSE, box = FALSE)
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.