1 files changed, 32 insertions, 0 deletions
diff --git a/c++/macroscopic.hpp b/c++/macroscopic.hpp
new file mode 100644
index 0000000..608b89e
--- /dev/null
+++ b/c++/macroscopic.hpp
@@ -0,0 +1,32 @@
+#pragma once
+
+namespace kel {
+namespace lbm {
+/**
+ * Calculate the macroscopic variables rho and u in Lattice Units.
+ */
+template<typename Desc>
+void compute_rho_u (
+		const saw::data<sch::DfCell<Desc>>& dfs,
+		typename saw::native_data_type<sch::T>::type& rho,
+		std::array<typename saw::native_data_type<sch::T>::type, 2>& vel
+	)
+{
+	using dfi = df_info<sch::T, Desc>;
+
+	rho = 0;
+	std::fill(vel.begin(), vel.end(), 0);
+
+	for(size_t j = 0; j < Desc::Q; ++j){
+		rho += dfs(j).get();
+		for(size_t i = 0; i < Desc::D; ++i){
+			vel[i] += dfi::directions[j][i] * dfs(j).get();
+		}
+	}
+
+	for(size_t i = 0; i < Desc::D; ++i){
+		vel[i] /= rho;
+	}
+}
+}
+}