add_locked_in_constraints: Add locked in constraints

In prioritizr/ppr: Optimal Project Prioritization

Add locked in constraints

Description

Add constraints to a project prioritization problem() to ensure that specific actions are prioritized for funding in the solution. For example, it may be desirable to lock in actions for conserving culturally or taxonomically important species.

Usage

add_locked_in_constraints(x, locked_in)

## S4 method for signature 'ProjectProblem,numeric'
add_locked_in_constraints(x, locked_in)

## S4 method for signature 'ProjectProblem,logical'
add_locked_in_constraints(x, locked_in)

## S4 method for signature 'ProjectProblem,character'
add_locked_in_constraints(x, locked_in)

Arguments

x	ProjectProblem object.
locked_in	Object that determines which planning units that should be locked in. See the Details section for more information.

Details

The locked actions can be specified in several different ways:

integer

vector of indices pertaining to which actions should be locked in the solution (i.e. row numbers of the actions in the argument to actions in problem()).

logical

vector containing logical (i.e. TRUE and/or FALSE values) that indicate which actions should be locked in the solution. These logical values should correspond to each row in the argument to actions in problem()).

character

column name that indicates if actions units should be locked in the solution. This argument should denote a column in the argument to actions in problem() which contains logical (i.e. TRUE and/or FALSE values) to indicate which actions should be locked.

Value

ProjectProblem object with the constraints added to it.

See Also

constraints.

Examples

# load data
data(sim_projects, sim_features, sim_actions)

# print action data
print(sim_actions)

# build problem with maximum richness objective and $150 budget
p1 <- problem(sim_projects, sim_actions, sim_features,
             "name", "success", "name", "cost", "name") %>%
     add_max_richness_objective(budget = 150) %>%
     add_binary_decisions()

# print problem
print(p1)

# build another problem, and lock in the 3rd action using numeric inputs
p2 <- p1 %>%
      add_locked_in_constraints(c(3))

# print problem
print(p2)

# build another problem, and lock in the actions using logical inputs from
# the sim_actions table
p3 <- p1 %>%
      add_locked_in_constraints(sim_actions$locked_in)

# print problem
print(p3)

# build another problem, and lock in the actions using the column name
# "locked_in" in the sim_actions table
# the sim_actions table
p4 <- p1 %>%
      add_locked_in_constraints("locked_in")

# print problem
print(p4)

## Not run: 
# solve problems
s1 <- solve(p1)
s2 <- solve(p2)
s3 <- solve(p3)
s4 <- solve(p4)

# print the actions selected for funding in each of the solutions
print(s1[, sim_actions$name])
print(s2[, sim_actions$name])
print(s3[, sim_actions$name])
print(s4[, sim_actions$name])

## End(Not run)

prioritizr/ppr documentation built on Sept. 10, 2022, 1:18 p.m.