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Plot prioritizr Solution

Source: R/splnr_plotting.R
splnr_plot_solution.Rd

The splnr_plot_solution() function visualizes the solution of a prioritizr conservation problem using ggplot2. It can handle single-zone and multi-zone solutions, offering customization for colors and legend.

Usage

splnr_plot_solution(
  soln,
  colorVals = c("#c6dbef", "#3182bd"),
  showLegend = TRUE,
  legendLabels = c("Not selected", "Selected"),
  plotTitle = "Solution",
  legendTitle = "Planning Units",
  zones = FALSE
)

Arguments

soln

The prioritizr solution object, expected as an sf object.

colorVals

A character vector of color values. For single-zone problems, this should typically be two colors (for "Not selected" and "Selected"). For multi-zone problems, the length should match the number of zones plus one (for "Not selected").

showLegend

A logical value indicating whether to display the legend of the solution. Defaults to TRUE.

legendLabels

A character vector of strings to label the legend values. Its length must match the number of levels in the solution (e.g., "Not selected", "Selected" for single zone; "Not selected", "Zone 1", "Zone 2" for two zones).

plotTitle

A character string for the title of the plot. Can be empty (""). Defaults to "Solution".

legendTitle

A character string for the title of the legend. Can be empty (""). Defaults to "Planning Units".

zones

A logical value. Set to TRUE if the prioritizr solution contains multiple zones (i.e., it's a multi-zone problem). Defaults to FALSE.

Value

A ggplot object representing the plot of the conservation solution.

Details

This function requires a prioritizr solution object, which should be an sf object containing at least a solution_1 column (for single-zone problems) or solution_1_zone1, solution_1_zone2, etc. (for multi-zone problems). It outputs a ggplot object, which can be further customized by combining it with the spatialplanr function splnr_gg_add().

For multi-zone problems (zones = TRUE), the function sums the selected zones for each Planning Unit and plots the resulting combined selection. The colorVals and legendLabels should be provided to match the number of selection levels (e.g., "Not selected", "Zone 1", "Zone 2", etc.).

Examples

if (FALSE) { # \dontrun{
# Assuming 'dat_species_bin' is an existing sf object in your package.

# Example 1: Plotting a single-zone prioritizr solution
dat_problem <- prioritizr::problem(
  dat_species_bin %>% dplyr::mutate(Cost = runif(n = dim(.)[[1]])),
  features = c("Spp1", "Spp2", "Spp3", "Spp4", "Spp5"),
  cost_column = "Cost"
) %>%
  prioritizr::add_min_set_objective() %>%
  prioritizr::add_relative_targets(0.3) %>%
  prioritizr::add_binary_decisions() %>%
  prioritizr::add_default_solver(verbose = FALSE)

dat_soln <- dat_problem %>%
  prioritizr::solve.ConservationProblem()

plot_soln_single_zone <- splnr_plot_solution(dat_soln)
print(plot_soln_single_zone)

# Example 2: Plotting a multi-zone prioritizr solution
# Create targets for two zones
t2 <- matrix(NA, ncol = 2, nrow = 5)
t2[, 1] <- 0.1
t2[, 2] <- 0.05

# Define zones for species
z2 <- prioritizr::zones(
  "zone 1" = c("Spp1", "Spp2", "Spp3", "Spp4", "Spp5"),
  "zone 2" = c("Spp1", "Spp2", "Spp3", "Spp4", "Spp5")
)

# Create a multi-zone problem (requires as many cost columns as zones)
p2 <- prioritizr::problem(
  dat_species_bin %>% dplyr::mutate(
    Cost1 = runif(n = dim(.)[[1]]),
    Cost2 = runif(n = dim(.)[[1]])
  ),
  z2,
  cost_column = c("Cost1", "Cost2")
) %>%
  prioritizr::add_min_set_objective() %>%
  prioritizr::add_relative_targets(t2) %>%
  prioritizr::add_binary_decisions() %>%
  prioritizr::add_default_solver(verbose = FALSE)

s2 <- p2 %>%
  prioritizr::solve.ConservationProblem()

plot_soln_multi_zone <- splnr_plot_solution(s2,
  zones = TRUE,
  colorVals = c("#c6dbef", "#3182bd", "black"), # Colors for Not selected, Zone 1, Zone 2
  legendLabels = c("Not selected", "Zone 1", "Zone 2")
)
print(plot_soln_multi_zone)
} # }