From 648f9c595ed484bdf787ed0ac009f253c1649857 Mon Sep 17 00:00:00 2001
From: Virginie Grandgirard <virginie.grandgirard@cea.fr>
Date: Fri, 13 Dec 2024 08:39:29 +0100
Subject: [PATCH] Add computation of max error for test_partial_derivatives.

---
 src/math_tools/partial_derivatives.hpp        |  6 +++---
 tests/math_tools/test_partial_derivatives.cpp | 16 +++++++++++++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/math_tools/partial_derivatives.hpp b/src/math_tools/partial_derivatives.hpp
index 159cc5658..0d6226328 100644
--- a/src/math_tools/partial_derivatives.hpp
+++ b/src/math_tools/partial_derivatives.hpp
@@ -36,8 +36,8 @@ class PartialDerivative
 private:
     using IdxRangeX1X2 = IdxRange<GridX1, GridX2>;
     using IdxX1X2 = typename IdxRangeX1X2::discrete_element_type;
-    using DFieldX1X2 = DField<double, IdxRangeX1X2>;
-    using DConstFieldX1X2 = DConstField<double, IdxRangeX1X2>;
+    using DFieldX1X2 = DField<IdxRangeX1X2>;
+    using DConstFieldX1X2 = DConstField<IdxRangeX1X2>;
 
     // Type for spline representation of the field
     using IdxRangeBSFieldX1 = typename FieldX1Builder::batched_spline_domain_type;
@@ -66,6 +66,6 @@ class PartialDerivative
         FieldX1SplineCoeffs fieldx1_coefs = get_field(fieldx1_coefs_alloc);
 
         m_fieldx1_builder(fieldx1_coefs, get_const_field(field_x1x2));
-        m_fieldx1_evaluator.deriv(dfield_dx1_x1x2, fieldx1_coefs);
+        m_fieldx1_evaluator.deriv(dfield_dx1_x1x2, get_const_field(fieldx1_coefs));
     }
 };
\ No newline at end of file
diff --git a/tests/math_tools/test_partial_derivatives.cpp b/tests/math_tools/test_partial_derivatives.cpp
index 36fecac22..78313444c 100644
--- a/tests/math_tools/test_partial_derivatives.cpp
+++ b/tests/math_tools/test_partial_derivatives.cpp
@@ -115,7 +115,21 @@ TEST(PartialDerivative, PartialDerivativeDx)
     PartialDerivative<GridX, GridX, GridY, SplineXBuilder, SplineXEvaluator> partial_dx(builder_x, spline_evaluator_x);
     DFieldMemXY dfield_dx_xy_alloc(idxrange_xy);
     DFieldXY dfield_dx_xy = get_field(dfield_dx_xy_alloc);
-    partial_dx(dfield_dx_xy, field_xy);
+    partial_dx(dfield_dx_xy, get_const_field(field_xy));
+
+    double max_error = 0;
+
+    ddc::parallel_for_each(
+            Kokkos::DefaultExecutionSpace(),
+            idxrange_xy,
+            KOKKOS_LAMBDA(IdxXY const idx_xy) {
+                IdxX idx_x(idx_xy);
+                IdxY idx_y(idx_xy);
+                dfield_dx_xy(idx_xy) = 
+                Kokkos::max(abs(dfield_dx_xy(idx_xy) -
+                    2. * ddc::coordinate(idx_x) * ddc::coordinate(idx_y)), max_error);
+            });
+    EXPECT_LE(max_error, 1e-12);
 }
 
 } // namespace