Add cmd line switch for implementation in DBSCAN example

examples/dbscan/dbscan.cpp

@@ -320,22 +320,24 @@ int main(int argc, char *argv[])
   int max_num_points;
   int num_samples;
   std::string filename_labels;
+  std::string implementation;
 
   bpo::options_description desc("Allowed options");
   // clang-format off
   desc.add_options()
       ( "help", "help message" )
-      ( "filename", bpo::value<std::string>(&filename), "filename containing data" )
       ( "binary", bpo::bool_switch(&binary)->default_value(false), "binary file indicator")
-      ( "max-num-points", bpo::value<int>(&max_num_points)->default_value(-1), "max number of points to read in")
-      ( "eps", bpo::value<float>(&eps), "DBSCAN eps" )
       ( "cluster-min-size", bpo::value<int>(&cluster_min_size)->default_value(2), "minimum cluster size")
       ( "core-min-size", bpo::value<int>(&core_min_size)->default_value(2), "DBSCAN min_pts")
-      ( "verify", bpo::bool_switch(&verify)->default_value(false), "verify connected components")
-      ( "samples", bpo::value<int>(&num_samples)->default_value(-1), "number of samples" )
+      ( "eps", bpo::value<float>(&eps), "DBSCAN eps" )
+      ( "filename", bpo::value<std::string>(&filename), "filename containing data" )
+      ( "impl", bpo::value<std::string>(&implementation)->default_value("fdbscan"), "implementation (\"fdbscan\" or \"fdbscan-densebox\")")
       ( "labels", bpo::value<std::string>(&filename_labels)->default_value(""), "clutering results output" )
-      ( "print-dbscan-timers", bpo::bool_switch(&print_dbscan_timers)->default_value(false), "print dbscan timers")
+      ( "max-num-points", bpo::value<int>(&max_num_points)->default_value(-1), "max number of points to read in")
       ( "output-sizes-and-centers", bpo::bool_switch(&print_sizes_centers)->default_value(false), "print cluster sizes and centers")
+      ( "print-dbscan-timers", bpo::bool_switch(&print_dbscan_timers)->default_value(false), "print dbscan timers")
+      ( "samples", bpo::value<int>(&num_samples)->default_value(-1), "number of samples" )
+      ( "verify", bpo::bool_switch(&verify)->default_value(false), "verify connected components")
       ;
   // clang-format on
   bpo::variables_map vm;
@@ -348,13 +350,25 @@ int main(int argc, char *argv[])
     return 1;
   }
 
+  if (implementation != "fdbscan" && implementation != "fdbscan-densebox")
+  {
+    std::cout << "Unknown implementation: \"" << implementation
+              << "\". Valid values are [\"fdbscan\", \"fdbscan-densebox\"]."
+              << std::endl;
+    return 2;
+  }
+  auto impl = (implementation == "fdbscan"
+                   ? ArborX::DBSCAN::Implementation::FDBSCAN
+                   : ArborX::DBSCAN::Implementation::FDBSCAN_DenseBox);
+
   // Print out the runtime parameters
   printf("eps               : %f\n", eps);
   printf("minpts            : %d\n", core_min_size);
   printf("cluster min size  : %d\n", cluster_min_size);
   printf("filename          : %s [%s, max_pts = %d]\n", filename.c_str(),
          (binary ? "binary" : "text"), max_num_points);
   printf("filename [labels] : %s [binary]\n", filename_labels.c_str());
+  printf("implementation    : %s\n", implementation.c_str());
   printf("samples           : %d\n", num_samples);
   printf("verify            : %s\n", (verify ? "true" : "false"));
   printf("print timers      : %s\n", (print_dbscan_timers ? "true" : "false"));
@@ -386,9 +400,10 @@ int main(int argc, char *argv[])
 
   timer_start(timer_total);
 
-  auto labels = ArborX::dbscan(
-      exec_space, primitives, eps, core_min_size,
-      ArborX::DBSCAN::Parameters().setPrintTimers(print_dbscan_timers));
+  auto labels = ArborX::dbscan(exec_space, primitives, eps, core_min_size,
+                               ArborX::DBSCAN::Parameters()
+                                   .setPrintTimers(print_dbscan_timers)
+                                   .setImplementation(impl));
 
   timer_start(timer);
   Kokkos::View<int *, MemorySpace> cluster_indices("Testing::cluster_indices",