getSolutionBenefit: Extract benefit values

In prioriactions: Multi-Action Conservation Planning

Extract benefit values

Description

Returns the total benefit induced by the corresponding solution. The total benefit is computed as the sum of the benefits obtained, for all features, across all the units in the planning area.

Usage

getSolutionBenefit(x, type = "total")

Arguments

x	Solution-class or Portfolio-class.
type	character. Output format of the benefits matrix; total shows the total benefit by feature, while local format shows the benefit achieved per feature and planning unit.

Details

For a given feature s, let I_s be the set of planning units associated with s, let r_{is} is the amount of feature s in planning unit i, let K_{s} be the set of threats associated with s, and let K_{i} be the set of threats associated with i. The local benefit associated with s in a unit i is given by:

b_{is} = p_{is} r_{is} \\ b_{is} = \frac{ \sum_{k \in K_i \cap K_s}{x_{ik}}}{|K_i \cap K_s|} r_{is}

Where x_{ik} is a decision variable such that x_{ik} = 1 if an action againts threat k is applied in unit i, and x_{ik} = 0, otherwise. This expression for the probability of persistence of the feature (p_{is}) is defined only for the cases where we work with values of binary intensities (presence or absence of threats). See the sensitivities vignette to know the work with continuous intensities.

While the total benefit is calculated as the sum of the local benefits per feature:

b_{s} = \sum_{i \in I_{s}}\frac{ \sum_{k \in K_i \cap K_s}{x_{ik}}}{|K_i \cap K_s|} r_{is}

Value

data.frame.

Examples

# set seed for reproducibility
set.seed(14)

## Load data
data(sim_pu_data, sim_features_data, sim_dist_features_data,
sim_threats_data, sim_dist_threats_data, sim_sensitivity_data,
sim_boundary_data)

## Create data instance
problem_data <- inputData(
  pu = sim_pu_data, features = sim_features_data, dist_features = sim_dist_features_data,
  threats = sim_threats_data, dist_threats = sim_dist_threats_data,
  sensitivity = sim_sensitivity_data, boundary = sim_boundary_data
)

## Get maximum benefits to obtain
getPotentialBenefit(problem_data)

## Create optimization model
problem_model <- problem(x = problem_data)

## Solve the optimization model
s <- solve(a = problem_model, time_limit = 2, output_file = FALSE, cores = 2)

# get local benefits of solution
local_benefit <- getSolutionBenefit(s, type = "local")
head(local_benefit)

# get total benefits of solution
total_benefit <- getSolutionBenefit(s, type = "total")
head(total_benefit)

prioriactions documentation built on Aug. 13, 2023, 5:06 p.m.