polar coordinates (wip)

Author: sbaldu

include/CLUEstering/core/DistanceMetrics.hpp

@@ -49,6 +49,24 @@ namespace clue {
     friend class internal::MetricInterface<WeightedEuclidianMetric<Ndim>, Ndim>;
   };
 
+  template <std::size_t Ndim>
+	requires (Ndim == 2)
+  class PolarEuclidianMetric : public internal::MetricInterface<PolarEuclidianMetric<Ndim>, Ndim> {
+  public:
+    ALPAKA_FN_HOST_ACC constexpr PolarEuclidianMetric() = default;
+
+  private:
+    ALPAKA_FN_HOST_ACC constexpr auto distance(const std::array<float, Ndim>& lhs,
+                                               const std::array<float, Ndim>& rhs) const {
+      const auto distance2 = meta::accumulate<Ndim>(
+          [&]<std::size_t Dim>() { return (lhs[Dim] - rhs[Dim]) * (lhs[Dim] - rhs[Dim]); });
+      return math::sqrt(distance2);
+    }
+
+    friend class internal::MetricInterface<PolarEuclidianMetric<Ndim>, Ndim>;
+  };
+
+
   template <std::size_t Ndim>
   class ManhattanMetric : public internal::MetricInterface<ManhattanMetric<Ndim>, Ndim> {
   public: