fix bug in greedy_heuristic_prioritization() feasibility calculations

prioritizr · Jul 24, 2024 · 2a3e7b4 · 2a3e7b4
1 parent 6fda197
commit 2a3e7b4
Show file tree

Hide file tree

Showing 33 changed files with 76 additions and 42 deletions.
diff --git a/DESCRIPTION b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: surveyvoi
 Type: Package
-Version: 1.1.0.0
+Version: 1.1.0.1
 Title: Survey Value of Information
 Description: Decision support tool for prioritizing sites for ecological
     surveys based on their potential to improve plans for conserving

diff --git a/NEWS.md b/NEWS.md
@@ -1,3 +1,13 @@
+# surveyvoi 1.1.0.1
+
+- Update `greedy_heuristic_algorithm()` function so that it returns a solution
+  if it is not possible to select enough planning units to meet the target
+  for any species. Instead of throwing an error, it will now throw a warning
+  and return a solution containing the cheapest set of planning units within
+  the budget and locked out constraints. Note that this solution
+  will have an objective value of zero, because it has zero probability of
+  meeting any of the species' targets.
+
 # surveyvoi 1.1.0.0
 
 - New `greedy_heuristic_algorithm()` function that can be used to generate

diff --git a/R/greedy_heuristic_optimization.R b/R/greedy_heuristic_optimization.R
@@ -142,15 +142,36 @@ greedy_heuristic_prioritization <- function(
     site_management_locked_out <- rep(FALSE, nrow(site_data))
   }
 
-  ## validate that targets are feasible given budget and locked out units
-  sorted_costs <- sort(
-    site_data[[site_management_cost_column]][!site_management_locked_out])
-  sorted_costs <- sorted_costs[
-    seq_len(max(feature_data[[feature_target_column]]))]
-  assertthat::assert_that(
-    sum(sorted_costs) <= total_budget,
-    msg = paste("targets cannot be achieved given budget and locked out",
-                "planning units"))
+  ## validate it is possible to select enough planning units to meet
+  ## the target for even a single feature,
+  ## if not, then it's not possible to generate a single solution
+  ## with an objective value = 0
+  cheapest_sol <- rep(FALSE, nrow(site_data))
+  cheapest_sol[site_management_locked_in] <- TRUE
+  if (min(feature_data[[feature_target_column]]) > sum(cheapest_sol)) {
+    idx <- which(!site_management_locked_out & !site_management_locked_in)
+    idx_costs <- site_data[[site_management_cost_column]]
+    idx_costs <- idx_costs[idx]
+    idx_order <- order(idx_costs)
+    idx_add <- cumsum(idx_costs[idx_order]) <= total_budget
+    sel_idx <- idx[idx_order[which(idx_add)]]
+    cheapest_sol[sel_idx] <- TRUE
+  }
+  if (
+    sum(cheapest_sol) < min(feature_data[[feature_target_column]])
+  ) {
+    ### throw warning
+    warning(
+      paste(
+        "it is not possible to select enough planning units to meet",
+        "any targets for even a single feature",
+        "(given the budget and locked out planning units)"
+      ),
+      call. = TRUE, immediate. = FALSE
+    )
+    ## return solution
+    return(list(x = cheapest_sol, objval = 0))
+  }
 
   # create prior data
   prior_data <-

diff --git a/docs/404.html b/docs/404.html
diff --git a/docs/articles/index.html b/docs/articles/index.html
diff --git a/docs/articles/surveyvoi.html b/docs/articles/surveyvoi.html
diff --git a/docs/authors.html b/docs/authors.html
diff --git a/docs/index.html b/docs/index.html
diff --git a/docs/news/index.html b/docs/news/index.html
diff --git a/docs/pkgdown.yml b/docs/pkgdown.yml
@@ -3,7 +3,7 @@ pkgdown: 2.0.7
 pkgdown_sha: ~
 articles:
   surveyvoi: surveyvoi.html
-last_built: 2024-07-09T23:25Z
+last_built: 2024-07-24T01:46Z
 urls:
   reference: https://github.com/prioritizr/surveyvoi/reference
   article: https://github.com/prioritizr/surveyvoi/articles

diff --git a/docs/reference/approx_evdsi.html b/docs/reference/approx_evdsi.html
diff --git a/docs/reference/approx_near_optimal_survey_scheme.html b/docs/reference/approx_near_optimal_survey_scheme.html
diff --git a/docs/reference/approx_optimal_survey_scheme.html b/docs/reference/approx_optimal_survey_scheme.html
diff --git a/docs/reference/env_div_survey_scheme.html b/docs/reference/env_div_survey_scheme.html
diff --git a/docs/reference/evdci.html b/docs/reference/evdci.html
diff --git a/docs/reference/evdsi.html b/docs/reference/evdsi.html
diff --git a/docs/reference/feasible_survey_schemes.html b/docs/reference/feasible_survey_schemes.html
diff --git a/docs/reference/fit_hglm_occupancy_models.html b/docs/reference/fit_hglm_occupancy_models.html
diff --git a/docs/reference/fit_xgb_occupancy_models.html b/docs/reference/fit_xgb_occupancy_models.html
diff --git a/docs/reference/geo_cov_survey_scheme.html b/docs/reference/geo_cov_survey_scheme.html
diff --git a/docs/reference/greedy_heuristic_prioritization.html b/docs/reference/greedy_heuristic_prioritization.html
diff --git a/docs/reference/index.html b/docs/reference/index.html
diff --git a/docs/reference/n_states.html b/docs/reference/n_states.html
diff --git a/docs/reference/optimal_survey_scheme.html b/docs/reference/optimal_survey_scheme.html
diff --git a/docs/reference/prior_probability_matrix.html b/docs/reference/prior_probability_matrix.html
diff --git a/docs/reference/relative_site_richness_scores.html b/docs/reference/relative_site_richness_scores.html
diff --git a/docs/reference/relative_site_uncertainty_scores.html b/docs/reference/relative_site_uncertainty_scores.html
diff --git a/docs/reference/sim_data.html b/docs/reference/sim_data.html
diff --git a/docs/reference/simulate_feature_data.html b/docs/reference/simulate_feature_data.html
diff --git a/docs/reference/simulate_site_data.html b/docs/reference/simulate_site_data.html
diff --git a/docs/reference/surveyvoi.html b/docs/reference/surveyvoi.html
diff --git a/docs/reference/weighted_survey_scheme.html b/docs/reference/weighted_survey_scheme.html
diff --git a/inst/doc/surveyvoi.html b/inst/doc/surveyvoi.html
@@ -12,7 +12,7 @@
 
 <meta name="author" content="Jeffrey O. Hanson" />
 
-<meta name="date" content="2024-07-10" />
+<meta name="date" content="2024-07-24" />
 
 <title>surveyvoi: Survey Value of Information</title>
 
@@ -171,7 +171,7 @@
 
 <h1 class="title toc-ignore">surveyvoi: Survey Value of Information</h1>
 <h4 class="author">Jeffrey O. Hanson</h4>
-<h4 class="date">2024-07-10</h4>
+<h4 class="date">2024-07-24</h4>
 
 
 <div id="TOC">