Use temperature bounds in multigroup mode temperature refs #2402

src/mgxs.cpp

@@ -95,6 +95,32 @@ void Mgxs::metadata_from_hdf5(hid_t xs_id, const vector<double>& temperature,
     settings::temperature_method = TemperatureMethod::NEAREST;
   }
 
+  // Determine actual temperatures to read -- start by checking whether a
+  // temperature range was given (indicated by T_max > 0), in which case all
+  // temperatures in the range are loaded irrespective of what temperatures
+  // actually appear in the model
+  int n = temperature.size();
+  double T_min = n > 0 ? settings::temperature_range[0] : 0.0;
+  double T_max = n > 0 ? settings::temperature_range[1] : INFTY;
+  if (T_max > 0.0) {
+    // Determine first available temperature below or equal to T_min
+    auto T_min_it =
+      std::upper_bound(available_temps.begin(), available_temps.end(), T_min);
+    if (T_min_it != available_temps.begin())
+      --T_min_it;
+
+    // Determine first available temperature above or equal to T_max
+    auto T_max_it =
+      std::lower_bound(available_temps.begin(), available_temps.end(), T_max);
+    if (T_max_it != available_temps.end())
+      ++T_max_it;
+
+    // Add corresponding temperatures to vector
+    for (auto it = T_min_it; it != T_max_it; ++it) {
+      temps_to_read.push_back(std::round(*it));
+    }
+  }
+
   switch (settings::temperature_method) {
   case TemperatureMethod::NEAREST:
     // Determine actual temperatures to read
@@ -356,7 +382,7 @@ Mgxs::Mgxs(const std::string& in_name, const vector<double>& mat_kTs,
           }
         }
       } // end switch
-    }   // end microscopic temperature loop
+    } // end microscopic temperature loop
 
     // Now combine the microscopic data at each relevant temperature
     // We will do this by treating the multiple temperatures of a nuclide as