From 920201e5fdee60cbae56db904d18347b9aada527 Mon Sep 17 00:00:00 2001
From: Rene Gassmoeller <rene.gassmoeller@mailbox.org>
Date: Mon, 7 Oct 2024 11:20:30 +0200
Subject: [PATCH] Improve error message

---
 include/aspect/simulator.h                          |  7 +++++++
 source/simulator/helper_functions.cc                | 13 +++++++++++++
 source/simulator/initial_conditions.cc              |  6 +++---
 .../screen-output                                   |  8 ++++----
 .../screen-output                                   |  4 ++--
 5 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/include/aspect/simulator.h b/include/aspect/simulator.h
index cd097b848c1..96a62f53d44 100644
--- a/include/aspect/simulator.h
+++ b/include/aspect/simulator.h
@@ -388,6 +388,13 @@ namespace aspect
          * field. See Introspection::polynomial_degree for more information.
          */
         unsigned int polynomial_degree(const Introspection<dim> &introspection) const;
+
+        /**
+         * Return a string that describes the field type and the compositional
+         * variable number and name, if applicable.
+         */
+        std::string
+        name(const Introspection<dim> &introspection) const;
       };
 
     private:
diff --git a/source/simulator/helper_functions.cc b/source/simulator/helper_functions.cc
index 22ef169e64c..581a7a628bd 100644
--- a/source/simulator/helper_functions.cc
+++ b/source/simulator/helper_functions.cc
@@ -205,6 +205,19 @@ namespace aspect
   }
 
 
+
+  template <int dim>
+  std::string
+  Simulator<dim>::AdvectionField::name(const Introspection<dim> &introspection) const
+  {
+    if (this->is_temperature())
+      return "temperature";
+    else
+      return "composition " + std::to_string(compositional_variable) + " (" + introspection.name_for_compositional_index(compositional_variable) + ")";
+  }
+
+
+
   template <int dim>
   void Simulator<dim>::write_plugin_graph (std::ostream &out) const
   {
diff --git a/source/simulator/initial_conditions.cc b/source/simulator/initial_conditions.cc
index 5d63861e1eb..8122598208c 100644
--- a/source/simulator/initial_conditions.cc
+++ b/source/simulator/initial_conditions.cc
@@ -312,7 +312,7 @@ namespace aspect
                 if (particle_property_manager.get_data_info().fieldname_exists(particle_property_and_component.first))
                   {
                     Assert (advection_field_has_been_found[advection_field] == false,
-                            ExcMessage("The same advection field is mapped to particle properties in different particle worlds. This is not supported."));
+                            ExcMessage("The field " + advection_fields[advection_field].name(introspection) + " is mapped to particle properties in more than one particle world. This is not supported."));
 
                     const unsigned int particle_property_index = particle_property_manager.get_data_info().get_position_by_field_name(particle_property_and_component.first)
                                                                  + particle_property_and_component.second;
@@ -344,8 +344,8 @@ namespace aspect
 
     for (unsigned int advection_field=0; advection_field<advection_fields.size(); ++advection_field)
       Assert (advection_field_has_been_found[advection_field] == true,
-              ExcMessage("An compositional field is marked as advected by particles, but no particle property exists that is mapped to this compositional field. "
-                         "Make sure that the particle property exists and is mapped to the compositional field in the parameter file."));
+              ExcMessage("The field " + advection_fields[advection_field].name(introspection) + " is marked as advected by particles, but no particle property exists that is mapped to this field. "
+                         "Make sure that the particle property exists and is mapped to the correct field in the parameter file."));
 
     LinearAlgebra::BlockVector particle_solution;
 
diff --git a/tests/particle_multiple_worlds_interpolation_fail_1/screen-output b/tests/particle_multiple_worlds_interpolation_fail_1/screen-output
index 1a7fcc6765b..1989052626f 100644
--- a/tests/particle_multiple_worlds_interpolation_fail_1/screen-output
+++ b/tests/particle_multiple_worlds_interpolation_fail_1/screen-output
@@ -12,10 +12,10 @@ An error occurred in file <initial_conditions.cc> in function
 The violated condition was: 
     advection_field_has_been_found[advection_field] == true
 Additional information: 
-    An compositional field is marked as advected by particles, but no
-    particle property exists that is mapped to this compositional field.
-    Make sure that the particle property exists and is mapped to the
-    compositional field in the parameter file.
+    The field composition 1 (function) is marked as advected by particles,
+    but no particle property exists that is mapped to this field. Make
+    sure that the particle property exists and is mapped to the correct
+    field in the parameter file.
 
 Stacktrace:
 (rest of the output replaced by default.sh script)
diff --git a/tests/particle_multiple_worlds_interpolation_fail_2/screen-output b/tests/particle_multiple_worlds_interpolation_fail_2/screen-output
index ab9fca9bb2f..765324782ee 100644
--- a/tests/particle_multiple_worlds_interpolation_fail_2/screen-output
+++ b/tests/particle_multiple_worlds_interpolation_fail_2/screen-output
@@ -12,8 +12,8 @@ An error occurred in file <initial_conditions.cc> in function
 The violated condition was: 
     advection_field_has_been_found[advection_field] == false
 Additional information: 
-    The same advection field is mapped to particle properties in different
-    particle worlds. This is not supported.
+    The field composition 0 (anomaly) is mapped to particle properties in
+    more than one particle world. This is not supported.
 
 Stacktrace:
 (rest of the output replaced by default.sh script)