From 17a12bfdd68a97e4d03a2f6e06110d926babb230 Mon Sep 17 00:00:00 2001
From: Tyagi <gthyagi@gmail.com>
Date: Fri, 27 Jun 2025 11:18:31 +1000
Subject: [PATCH 1/2] updated checkpoint_xdmf method save discontinuous fields
 properly

---
 src/underworld3/discretisation.py | 33 ++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/underworld3/discretisation.py b/src/underworld3/discretisation.py
index 6a195abb..469f3b97 100644
--- a/src/underworld3/discretisation.py
+++ b/src/underworld3/discretisation.py
@@ -2893,40 +2893,55 @@ def checkpoint_xdmf(
 """
 
     ## The mesh Var attributes
+    
+    def get_cell_field_size(h5_filename):
+        with h5py.File(h5_filename, 'r') as f:
+            size = f[f'cell_fields/{var.clean_name}_{var.clean_name}'].shape[0]
+        return size
 
     attributes = ""
     for var in meshVars:
-        var_filename = filename + f"mesh.{var.clean_name}.{index:05}.h5"
+        var_filename = filename + f".mesh.{var.clean_name}.{index:05}.h5"
+
         if var.num_components == 1:
             variable_type = "Scalar"
         else:
             variable_type = "Vector"
-        # We should add a tensor type here ...
+
+        # Determine if data is stored on nodes (vertex_fields) or cells (cell_fields)
+        if not getattr(var, "continuous") or getattr(var, "degree")==0:
+            center = "Cell"
+            numItems = get_cell_field_size(var_filename)
+            field_group = "cell_fields"
+        else:
+            center = "Node"
+            numItems = numVertices
+            field_group = "vertex_fields"
 
         var_attribute = f"""
         <Attribute
            Name="{var.clean_name}"
            Type="{variable_type}"
-           Center="Node">
+           Center="{center}">
           <DataItem ItemType="HyperSlab"
-        	    Dimensions="1 {numVertices} {var.num_components}"
-        	    Type="HyperSlab">
+                Dimensions="1 {numItems} {var.num_components}"
+                Type="HyperSlab">
             <DataItem
                Dimensions="3 3"
                Format="XML">
               0 0 0
               1 1 1
-              1 {numVertices} {var.num_components}
+              1 {numItems} {var.num_components}
             </DataItem>
             <DataItem
                DataType="Float" Precision="8"
-               Dimensions="1 {numVertices} {var.num_components}"
+               Dimensions="1 {numItems} {var.num_components}"
                Format="HDF">
-              &{var.clean_name+"_Data"};:/vertex_fields/{var.clean_name+"_"+var.clean_name}
+              &{var.clean_name+"_Data"};:/{field_group}/{var.clean_name+"_"+var.clean_name}
             </DataItem>
           </DataItem>
         </Attribute>
-    """
+        """
         attributes += var_attribute
 
     for var in swarmVars:

From aa65291a38853723fc29850d92e75a0ce3beec5a Mon Sep 17 00:00:00 2001
From: Tyagi <gthyagi@gmail.com>
Date: Fri, 27 Jun 2025 11:50:04 +1000
Subject: [PATCH 2/2] added var as argument to def

---
 src/underworld3/discretisation.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/underworld3/discretisation.py b/src/underworld3/discretisation.py
index 469f3b97..5cd34da4 100644
--- a/src/underworld3/discretisation.py
+++ b/src/underworld3/discretisation.py
@@ -2894,9 +2894,9 @@ def checkpoint_xdmf(
 
     ## The mesh Var attributes
     
-    def get_cell_field_size(h5_filename):
+    def get_cell_field_size(h5_filename, mesh_var):
         with h5py.File(h5_filename, 'r') as f:
-            size = f[f'cell_fields/{var.clean_name}_{var.clean_name}'].shape[0]
+            size = f[f'cell_fields/{mesh_var.clean_name}_{mesh_var.clean_name}'].shape[0]
         return size
 
     attributes = ""
@@ -2911,7 +2911,7 @@ def get_cell_field_size(h5_filename):
         # Determine if data is stored on nodes (vertex_fields) or cells (cell_fields)
         if not getattr(var, "continuous") or getattr(var, "degree")==0:
             center = "Cell"
-            numItems = get_cell_field_size(var_filename)
+            numItems = get_cell_field_size(var_filename, var)
             field_group = "cell_fields"
         else:
             center = "Node"