Fix: add missing enable_tensor_type for CartesianLeviCivitaTensor and fix Levi-Civita size() #578

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Add missing `enable_tensor_type` for `CartesianLeviCivitaTensor` and LeviCivita `size()`.
+
 ### Changed
 
 - Add Koliop in all toolchains.

src/data_types/static_tensors.hpp

@@ -84,7 +84,7 @@ class IdentityTensor
      * @tparam Dim The dimension of interest (0 <= dim < rank()).
      */
     template <std::size_t dim>
-    using vector_index_set_t = std::conditional_t<dim == 0, ValidIndexSetRow, ValidIndexSetCol>;
+    using vector_index_set_t = ddc::type_seq_element_t<dim, index_set>;
 };
 
 /**
@@ -99,6 +99,16 @@ class CartesianLeviCivitaTensor
     static_assert(is_vector_index_set_v<ValidIndexSet>);
     static_assert(std::is_same_v<ValidIndexSet, vector_index_set_dual_t<ValidIndexSet>>);
 
+private:
+    KOKKOS_FUNCTION static constexpr std::size_t compute_size()
+    {
+        std::size_t result = 1;
+        for (std::size_t i = 0; i < rank(); ++i) {
+            result *= ddc::type_seq_size_v<ValidIndexSet>;
+        }
+        return result;
+    }
+
 public:
     /// The type of the elements of the tensor.
     using element_type = ElementType;
@@ -123,7 +133,7 @@ class CartesianLeviCivitaTensor
      */
     KOKKOS_FUNCTION static constexpr std::size_t size()
     {
-        return rank() * rank();
+        return compute_size();
     }
 
     /// The TensorIndexSet describing the possible indices.
@@ -171,7 +181,15 @@ class LeviCivitaTensor
             || (is_contravariant_vector_index_set_v<ValidIndexSet>));
 
 private:
-    double m_coeff;
+    ElementType m_coeff;
+    KOKKOS_FUNCTION static constexpr std::size_t compute_size()
+    {
+        std::size_t result = 1;
+        for (std::size_t i = 0; i < rank(); ++i) {
+            result *= ddc::type_seq_size_v<ValidIndexSet>;
+        }
+        return result;
+    }
 
 public:
     /// The type of the elements of the tensor.
@@ -197,7 +215,7 @@ class LeviCivitaTensor
      */
     KOKKOS_FUNCTION static constexpr std::size_t size()
     {
-        return rank() * rank();
+        return compute_size();
     }
 
     /// The TensorIndexSet describing the possible indices.
@@ -206,7 +224,7 @@ class LeviCivitaTensor
     /**
      * @brief Construct an uninitialised tensor object.
      */
-    explicit KOKKOS_FUNCTION LeviCivitaTensor(double jacobian)
+    explicit KOKKOS_FUNCTION LeviCivitaTensor(ElementType jacobian)
     {
         if constexpr (is_covariant_vector_index_set_v<ValidIndexSet>) {
             m_coeff = jacobian;
@@ -225,7 +243,7 @@ class LeviCivitaTensor
     template <class QueryTensorIndexElement>
     KOKKOS_INLINE_FUNCTION ElementType get() const
     {
-        double constexpr eps = type_seq_permutation_parity_v<
+        int constexpr eps = type_seq_permutation_parity_v<
                 typename QueryTensorIndexElement::IdxTypeSeq,
                 ValidIndexSet>;
         return eps * m_coeff;
@@ -243,7 +261,7 @@ class LeviCivitaTensor
 
 namespace ddcHelper {
 /**
- * @brief A helper function to get a modifiable reference to an element of the tensor.
+ * @brief A helper function to get the value of an element of the tensor.
  * @tparam QueryIndexTag A type describing the relevant index.
  * @param tensor The tensor whose elements are examined.
  * @return The relevant element of the tensor.
@@ -258,7 +276,7 @@ KOKKOS_INLINE_FUNCTION constexpr double get(
 }
 
 /**
- * @brief A helper function to get a modifiable reference to an element of the tensor.
+ * @brief A helper function to get the value of an element of the tensor.
  * @tparam QueryIndexTag A type describing the relevant index.
  * @param tensor The tensor whose elements are examined.
  * @return The relevant element of the tensor.
@@ -273,7 +291,7 @@ KOKKOS_INLINE_FUNCTION constexpr double get(
 }
 
 /**
- * @brief A helper function to get a modifiable reference to an element of the tensor.
+ * @brief A helper function to get the value of an element of the tensor.
  * @tparam QueryIndexTag A type describing the relevant index.
  * @param tensor The tensor whose elements are examined.
  * @return The relevant element of the tensor.
@@ -297,4 +315,8 @@ inline constexpr bool
 template <class ElementType, class ValidIndexSet>
 inline constexpr bool enable_tensor_type<LeviCivitaTensor<ElementType, ValidIndexSet>> = true;
 
+template <class ElementType, class ValidIndexSet>
+inline constexpr bool
+        enable_tensor_type<CartesianLeviCivitaTensor<ElementType, ValidIndexSet>> = true;
+
 } // namespace detail

tests/data_types/tensor.cpp

@@ -506,3 +506,45 @@ TEST(TensorTest, ElementAssign)
     EXPECT_EQ((ddcHelper::get<Y, X>(small)), (ddcHelper::get<Y, X>(big)));
     EXPECT_EQ((ddcHelper::get<Y, Y>(small)), (ddcHelper::get<Y, Y>(big)));
 }
+
+TEST(TensorTest, CartesianLeviCivitaEnabledAsTensorType)
+{
+    using CartLC = CartesianLeviCivitaTensor<int, VectorIndexSet<X, Y, Z>>;
+    static_assert(
+            is_tensor_type_v<CartLC>,
+            "CartesianLeviCivitaTensor should be recognised as a tensor type");
+    using LC = LeviCivitaTensor<int, VectorIndexSet<R, Theta>>;
+    using Id = IdentityTensor<int, VectorIndexSet<R, Z>, VectorIndexSet<R, Z>>;
+    static_assert(is_tensor_type_v<LC>);
+    static_assert(is_tensor_type_v<Id>);
+}
+
+TEST(TensorTest, LeviCivitaSize3D)
+{
+    using CartLC3D = CartesianLeviCivitaTensor<int, VectorIndexSet<X, Y, Z>>;
+    using LC3D = LeviCivitaTensor<double, VectorIndexSet<R, Theta, Z>>;
+    static_assert(CartLC3D::size() == 27);
+    static_assert(LC3D::size() == 27);
+    static_assert(CartLC3D::rank() == 3);
+    static_assert(LC3D::rank() == 3);
+    using CartLC2D = CartesianLeviCivitaTensor<int, VectorIndexSet<X, Y>>;
+    using LC2D = LeviCivitaTensor<double, VectorIndexSet<R, Theta>>;
+    static_assert(CartLC2D::size() == 4);
+    static_assert(LC2D::size() == 4);
+}
+
+TEST(TensorTest, LeviCivitaFloatElementType)
+{
+    LeviCivitaTensor<float, VectorIndexSet<R, Theta>> lc_float(2.0f);
+    static_assert(std::is_same_v<decltype(lc_float)::element_type, float>);
+    float val_rt = ddcHelper::get<R, Theta>(lc_float);
+    float val_tr = ddcHelper::get<Theta, R>(lc_float);
+    float val_rr = ddcHelper::get<R, R>(lc_float);
+
+    EXPECT_FLOAT_EQ(val_rt, 0.5f);
+    EXPECT_FLOAT_EQ(val_tr, -0.5f);
+    EXPECT_FLOAT_EQ(val_rr, 0.0f);
+
+    CartesianLeviCivitaTensor<float, VectorIndexSet<X, Y>> cart_lc_float;
+    static_assert(std::is_same_v<decltype(cart_lc_float)::element_type, float>);
+}