interpolation1d

done single-threded 1d interpolations; linear, rational, cubic spline, polynomial and barycentric. Still not done test functions yet. Still missing multi-core options.

include/modules/grid1d.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include "utils/vector.h"
+
+
+namespace fvm {
+
+	template <typename T>
+
+	struct Grid1D{
+		uint64_t center_idx;				// max cell index
+		uint64_t vertices_idx;				// max vertice index
+		utils::Vector<T> centers;			// size N (unknowns at cell centers)
+		utils::Vector<T> vertices;			// size N+1 (face positions)
+
+		Grid1D() = default;
+
+		explicit Grid1D(const utils::Vector<T>& midpoints){
+			centers = midpoints;
+			center_idx = centers.size()-1;
+			vertices_idx = centers.size();		
+		}
+
+		void generate_vertices(T left, T right){
+			vertices.resize(vertices_idx+1);
+			vertices[0] = left;	
+			vertices[vertices_idx] = right;
+			for (uint64_t i = 1; i < center_idx+1; ++i){
+				vertices[i] = (centers[i-1] + centers[i])*0.5;
+			}
+
+		}
+
+		T dx(uint64_t i) const { check(i); return vertices[i+1] - vertices[i]; }
+		T center(uint64_t i) const { check(i); return centers[i]; }
+
+	    void check(uint64_t i) const {
+	        if (i > center_idx) throw std::runtime_error("Grid1D: cell index out of range");
+	    }
+	};
+
+
+}