add_manual_bounded_constraints | R Documentation |
Add constraints to a conservation planning problem to ensure
that the planning unit values (e.g., proportion, binary) in a solution
range between specific lower and upper bounds. This function offers more
fine-grained control than the add_manual_locked_constraints()
function and is is most useful for problems involving proportion-type
or semi-continuous decisions.
add_manual_bounded_constraints(x, data)
## S4 method for signature 'ConservationProblem,data.frame'
add_manual_bounded_constraints(x, data)
## S4 method for signature 'ConservationProblem,tbl_df'
add_manual_bounded_constraints(x, data)
x |
|
data |
|
An updated problem()
object with the constraints added to it.
The argument to data
should be a data.frame
with the following columns:
integer
planning unit identifier.
character
names of zones. Note that this
argument is optional for arguments to x
that contain a single
zone.
numeric
values indicating the minimum
value that each planning unit can be allocated to in each zone
in the solution.
numeric
values indicating the maximum
value that each planning unit can be allocated to in each zone
in the solution.
See constraints for an overview of all functions for adding constraints.
Other constraints:
add_contiguity_constraints()
,
add_feature_contiguity_constraints()
,
add_linear_constraints()
,
add_locked_in_constraints()
,
add_locked_out_constraints()
,
add_mandatory_allocation_constraints()
,
add_manual_locked_constraints()
,
add_neighbor_constraints()
## Not run:
# set seed for reproducibility
set.seed(500)
# load data
sim_pu_polygons <- get_sim_pu_polygons()
sim_features <- get_sim_features()
sim_zones_pu_polygons <- get_sim_zones_pu_polygons()
sim_zones_features <- get_sim_zones_features()
# create minimal problem
p1 <-
problem(sim_pu_polygons, sim_features, "cost") %>%
add_min_set_objective() %>%
add_relative_targets(0.2) %>%
add_binary_decisions() %>%
add_default_solver(verbose = FALSE)
# create problem with locked in constraints using add_locked_constraints
p2 <- p1 %>% add_locked_in_constraints("locked_in")
# create identical problem using add_manual_bounded_constraints
bounds_data <- data.frame(
pu = which(sim_pu_polygons$locked_in),
lower = 1,
upper = 1
)
p3 <- p1 %>% add_manual_bounded_constraints(bounds_data)
# solve problems
s1 <- solve(p1)
s2 <- solve(p2)
s3 <- solve(p3)
# create object with all solutions
s4 <- sf::st_sf(
tibble::tibble(
s1 = s1$solution_1,
s2 = s2$solution_1,
s3 = s3$solution_1
),
geometry = sf::st_geometry(s1)
)
# plot solutions
## s1 = none locked in
## s2 = locked in constraints
## s3 = manual bounds constraints
plot(s4)
# create minimal problem with multiple zones
p5 <-
problem(
sim_zones_pu_polygons, sim_zones_features,
c("cost_1", "cost_2", "cost_3")
) %>%
add_min_set_objective() %>%
add_relative_targets(matrix(runif(15, 0.1, 0.2), nrow = 5, ncol = 3)) %>%
add_binary_decisions() %>%
add_default_solver(verbose = FALSE)
# create data.frame with the following constraints:
# planning units 1, 2, and 3 must be allocated to zone 1 in the solution
# planning units 4, and 5 must be allocated to zone 2 in the solution
# planning units 8 and 9 must not be allocated to zone 3 in the solution
bounds_data2 <- data.frame(
pu = c(1, 2, 3, 4, 5, 8, 9),
zone = c(rep("zone_1", 3), rep("zone_2", 2), rep("zone_3", 2)),
lower = c(rep(1, 5), rep(0, 2)),
upper = c(rep(1, 5), rep(0, 2))
)
# print bounds data
print(bounds_data2)
# create problem with added constraints
p6 <- p5 %>% add_manual_bounded_constraints(bounds_data2)
# solve problem
s5 <- solve(p5)
s6 <- solve(p6)
# create two new columns representing the zone id that each planning unit
# was allocated to in the two solutions
s5$solution <- category_vector(sf::st_drop_geometry(
s5[, c("solution_1_zone_1","solution_1_zone_2", "solution_1_zone_3")]
))
s5$solution <- factor(s5$solution)
s5$solution_bounded <- category_vector(sf::st_drop_geometry(
s6[, c("solution_1_zone_1", "solution_1_zone_2", "solution_1_zone_3")]
))
s5$solution_bounded <- factor(s5$solution_bounded)
# plot solutions
plot(s5[, c("solution", "solution_bounded")], axes = FALSE)
## End(Not run)
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