Sort non-compound materials by numID

gprMax/materials.py

@@ -57,21 +57,54 @@ class Material:
                 f"'==' not supported between instances of 'Material' and '{type(value)}'"
             )
 
-    def __lt__(self, value: object) -> bool:
-        if isinstance(value, Material):
-            return self.ID < value.ID
-        else:
+    def __lt__(self, value: "Material") -> bool:
+        """Less than comparator for two Materials.
+
+        Only non-compound materials (i.e. default or user added
+        materials) are guaranteed to have the same numID for the same
+        material across MPI ranks. Therefore compound materials are
+        sorted by ID and non-compound materials are always less than
+        compound materials.
+        """
+        if not isinstance(value, Material):
             raise TypeError(
                 f"'<' not supported between instances of 'Material' and '{type(value)}'"
             )
-
-    def __gt__(self, value: object) -> bool:
-        if isinstance(value, Material):
-            return self.ID > value.ID
+        elif self.is_compound_material() and value.is_compound_material():
+            return self.ID < value.ID
         else:
+            return value.is_compound_material() or self.numID < value.numID
+
+    def __gt__(self, value: "Material") -> bool:
+        """Greater than comparator for two Materials.
+
+        Only non-compound materials (i.e. default or user added
+        materials) are guaranteed to have the same numID for the same
+        material across MPI ranks. Therefore compound materials are
+        sorted by ID and are always greater than non-compound materials.
+        """
+        if not isinstance(value, Material):
             raise TypeError(
                 f"'>' not supported between instances of 'Material' and '{type(value)}'"
             )
+        elif self.is_compound_material() and value.is_compound_material():
+            return self.ID > value.ID
+        else:
+            return self.is_compound_material() or self.numID > value.numID
+
+    def is_compound_material(self) -> bool:
+        """Check if a material is a compound material.
+
+        The ID of a compound material comprises of the component
+        material IDs joined by a '+' symbol. Therefore we check for a
+        compound material by looking for a '+' symbol in the material
+        ID.
+
+        Returns:
+            is_compound_material: True if material is a compound
+                material. False otherwise.
+        """
+        return self.ID.count("+") > 0
 
     @staticmethod
     def create_compound_id(*materials: "Material") -> str:

reframe_tests/regression_checks/TestGeometryObject_a6a096cb/full_volume.h5

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:2b2fbdb39eb6ad15c35877be207a7a0d3f19cc22faad223d058988f788842f7b
+oid sha256:a23ccc9ed81685385ff300c0c00e70329945db364dd7eb9607a511870469c720
 size 75462640

reframe_tests/regression_checks/TestGeometryObject_a6a096cb/full_volume_materials.txt

@@ -1,8 +1,8 @@
+#material: 1 0 1 0 free_space
+#material: 4.9 0 1 0 myWater
 #material: 3 0 2 0 boxMaterial
 #material: 2 0 1.5 0 boxMaterial+boxMaterial+free_space+free_space
 #material: 1.5 0 1.25 0 boxMaterial+free_space+free_space+free_space
-#material: 1 0 1 0 free_space
 #material: 1.975 0 1 0 free_space+free_space+free_space+myWater
 #material: 2.95 0 1 0 free_space+free_space+myWater+myWater
 #material: 3.925 0 1 0 free_space+myWater+myWater+myWater
-#material: 4.9 0 1 0 myWater

reframe_tests/regression_checks/TestGeometryObject_a6a096cb/partial_volume.h5

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:6304565819cdb7c5b2af86d57bb25e3f22c92b9aae431934e2c2eca029928d59
+oid sha256:4b8f8c4979f4c82eb4be8a9a63cfaf19408b9f493d1bf3082a8226e97542ae4a
 size 4980400

reframe_tests/regression_checks/TestGeometryObject_a6a096cb/partial_volume_materials.txt

@@ -1,8 +1,8 @@
+#material: 1 0 1 0 free_space
+#material: 4.9 0 1 0 myWater
 #material: 3 0 2 0 boxMaterial
 #material: 2 0 1.5 0 boxMaterial+boxMaterial+free_space+free_space
 #material: 1.5 0 1.25 0 boxMaterial+free_space+free_space+free_space
-#material: 1 0 1 0 free_space
 #material: 1.975 0 1 0 free_space+free_space+free_space+myWater
 #material: 2.95 0 1 0 free_space+free_space+myWater+myWater
 #material: 3.925 0 1 0 free_space+myWater+myWater+myWater
-#material: 4.9 0 1 0 myWater