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Add objective: maximize net profit

Source: R/add_objectives.R
add_objective_max_net_profit.Rd

Define an objective that maximizes net profit by combining profits with optional planning-unit and action-cost penalties.

Usage

add_objective_max_net_profit(
  x,
  profit_col = "profit",
  include_pu_cost = TRUE,
  include_action_cost = TRUE,
  actions = NULL,
  alias = NULL
)

Arguments

x

A Problem object.

profit_col

Character string giving the profit column in the stored profit table.

include_pu_cost

Logical. If TRUE, subtract planning-unit costs.

include_action_cost

Logical. If TRUE, subtract action costs.

actions

Optional subset of actions to include in the profit and action-cost terms. Values may match x$data$actions$id and, if present, x$data$actions$action_set.

alias

Optional identifier used to register this objective for multi-objective workflows.

Value

An updated Problem object.

Details

Use this function when decisions generate returns and the objective should optimize the resulting net balance after subtracting selected cost components.

Let:

  • \(x_{ia} \in \{0,1\}\) denote whether action \(a\) is selected in planning unit \(i\),

  • \(w_i \in \{0,1\}\) denote whether planning unit \(i\) is selected,

  • \(\pi_{ia}\) denote the profit associated with decision \((i,a)\),

  • \(c_i^{PU} \ge 0\) denote the planning-unit cost,

  • \(c_{ia}^{A} \ge 0\) denote the action cost.

In its most general form, the objective is:

$$ \max \left( \sum_{(i,a) \in \mathcal{D}^{\star}} \pi_{ia} x_{ia} - \sum_{i \in \mathcal{I}} c_i^{PU} w_i - \sum_{(i,a) \in \mathcal{D}^{\star}} c_{ia}^{A} x_{ia} \right), $$

where \(\mathcal{D}^{\star}\) denotes the subset of feasible planning unit–action decisions included in the objective.

If actions = NULL, all feasible actions contribute to both the profit term and the action-cost term.

If actions is provided, the profit term and the action-cost term are restricted to that subset. The planning-unit cost term, if included, remains global.

If include_pu_cost = FALSE, the planning-unit cost term is omitted.

If include_action_cost = FALSE, the action-cost term is omitted.

See also

add_objective_max_profit, add_objective_min_cost

Examples

pu_tbl <- data.frame(
  id = 1:4,
  cost = c(1, 2, 3, 4)
)
feat_tbl <- data.frame(
  id = 1:2,
  name = c("feature_1", "feature_2")
)
dist_feat_tbl <- data.frame(
  pu = c(1, 1, 2, 3, 4),
  feature = c(1, 2, 2, 1, 2),
  amount = c(5, 2, 3, 4, 1)
)
actions_df <- data.frame(
  id = c("conservation", "restoration"),
  name = c("conservation", "restoration")
)
profit_df <- data.frame(
  pu = c(1, 2, 3, 4, 1, 2, 3, 4),
  action = c("conservation", "conservation", "conservation", "conservation",
             "restoration", "restoration", "restoration", "restoration"),
  profit = c(5, 4, 3, 2, 8, 7, 6, 5)
)

p <- create_problem(
  pu = pu_tbl,
  features = feat_tbl,
  dist_features = dist_feat_tbl,
  cost = "cost"
) |>
  add_actions(actions_df, cost = c(conservation = 1, restoration = 2)) |>
  add_profit(profit_df)

p1 <- add_objective_max_net_profit(p)
p1$data$model_args
#> $model_type
#> [1] "maximizeNetProfit"
#> 
#> $objective_id
#> [1] "max_net_profit"
#> 
#> $objective_args
#> $objective_args$profit_col
#> [1] "profit"
#> 
#> $objective_args$include_pu_cost
#> [1] TRUE
#> 
#> $objective_args$include_action_cost
#> [1] TRUE
#> 
#> $objective_args$actions
#> NULL
#> 
#> 

p2 <- add_objective_max_net_profit(
  p,
  include_pu_cost = FALSE,
  include_action_cost = TRUE
)
p2$data$model_args
#> $model_type
#> [1] "maximizeNetProfit"
#> 
#> $objective_id
#> [1] "max_net_profit"
#> 
#> $objective_args
#> $objective_args$profit_col
#> [1] "profit"
#> 
#> $objective_args$include_pu_cost
#> [1] FALSE
#> 
#> $objective_args$include_action_cost
#> [1] TRUE
#> 
#> $objective_args$actions
#> NULL
#> 
#> 

p3 <- add_objective_max_net_profit(
  p,
  actions = "restoration"
)
p3$data$model_args
#> $model_type
#> [1] "maximizeNetProfit"
#> 
#> $objective_id
#> [1] "max_net_profit"
#> 
#> $objective_args
#> $objective_args$profit_col
#> [1] "profit"
#> 
#> $objective_args$include_pu_cost
#> [1] TRUE
#> 
#> $objective_args$include_action_cost
#> [1] TRUE
#> 
#> $objective_args$actions
#> [1] "restoration"
#> 
#>