1 files changed, 9 insertions, 0 deletions
diff --git a/Carpet/CarpetIOHDF5/src/Output.cc b/Carpet/CarpetIOHDF5/src/Output.cc
index 898952c1f..24cbcd9cb 100644
--- a/Carpet/CarpetIOHDF5/src/Output.cc
+++ b/Carpet/CarpetIOHDF5/src/Output.cc
@@ -664,6 +664,15 @@ static int AddAttributes (const cGH *const cctkGH, const char *fullname,
     free (groupname);
   }
 
+  // Specify whether the coordinate system is Cartesian or not
+  if (CCTK_IsFunctionAliased ("MultiPatch_MapIsCartesian")) {
+    int const map_is_cartesian = MultiPatch_MapIsCartesian (Carpet::map);
+    HDF5_ERROR (attr = H5Acreate (dataset, "MapIsCartesian", H5T_NATIVE_INT,
+                                  dataspace, H5P_DEFAULT));
+    HDF5_ERROR (H5Awrite (attr, H5T_NATIVE_INT, & map_is_cartesian));
+    HDF5_ERROR (H5Aclose (attr));
+  }
+
   hsize_t size = vdim;
   HDF5_ERROR (dataspace = H5Screate_simple (1, &size, NULL));