Documentation

docs/source/usage/concepts.rst

@@ -20,6 +20,9 @@ A record is an data set with common properties, e.g. the electric field :math:`\
 A density field could be another record - which is scalar as it only has one component.
 
 In general, openPMD allows records with arbitrary number of components (tensors), as well as vector records and scalar records.
+In the case of vector records, the single components are stored as datasets within the record.
+In the case of scalar records, the record and component are equivalent.
+In the API, the record can be directly used as a component, and in the standard a scalar record is represented by the scalar dataset with attributes.
 
 Meshes and Particles
 --------------------

include/openPMD/backend/BaseRecord.hpp

@@ -207,6 +207,16 @@ namespace internal
     };
 } // namespace internal
 
+/**
+ * @brief Base class for any type of record (e.g. mesh or particle record).
+ *
+ * If the record is a vector record, the single components are accessed via the
+ * container interface (base class 1).
+ * If the record is a scalar record, it directly acts as a record component
+ * (base class 2) and the Container API needs not be used.
+ *
+ * @tparam T_elem
+ */
 template <typename T_elem>
 class BaseRecord
     : public Container<T_elem>