missing file added

src/amdis/operations/CMakeLists.txt

@@ -5,6 +5,7 @@ install(FILES
     Basic.hpp
     CMath.hpp
     Composer.hpp
+    Composer.impl.hpp
     FieldMatVec.hpp
     MaxMin.hpp
 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/amdis/operations)

src/amdis/operations/Composer.impl.hpp

+#pragma once
+
+#include <amdis/operations/Composer.hpp>
+
+#include <amdis/operations/Arithmetic.hpp>
+
+namespace AMDiS { namespace Operation {
+
+  /// Partial derivative of composed function:
+  /// Implements: // sum_i [ d_i(f)[g...] * d_j(g_i) ]
+  template <int J, class F, class... Gs>
+  auto partial(Composer<F,Gs...> const& c, index_t<J> _j)
+  {
+    auto index_seq = MakeSeq_t<sizeof...(Gs)>{};
+
+    // d_i(f)[g...] * d_j(g_i)
+    auto term_i = [&](auto const _i)
+    {
+      auto di_f = Dune::Std::apply([&](auto const&... gs) {
+        return compose(partial(c.f_, _i), gs...);
+      }, c.gs_);
+
+      auto const& g_i = std::get<_i>(c.gs_);
+      return compose(Multiplies{}, di_f, partial(g_i, _j));
+    };
+
+    // sum_i [ d_i(f)[g...] * d_j(g_i) ]
+    return Dune::Std::apply([&](auto const... _i)
+    {
+      return compose(Plus{}, term_i(_i)...);
+    }, index_seq);
+  }
+
+}} // end namespace AMDiS::Operation