euler integration maybe working

advection/README.md

@@ -17,23 +17,4 @@ mkdir build
 cd build
 cmake ..
 make
-```
+```
-
-### Building with Linux
-Makes use of `mdspan` which is not supported by glibc++ at time of writing. See [compiler support](https://en.cppreference.com/w/cpp/compiler_support/23) for `mdspan`. The solution to this is to use Clang and libc++; this is configured in our CMake setup, however the default installation of the `netcdf-cxx` package on at least Arch linux (and suspectedly Debian derivatives as well) specifically builds for the glibc implementation. To get the netcdf C++ bindings functional with the libc++ implementation, one needs to build from source. On Linux, this requires a few changes to the CMake file included with the netcdf-cxx source code, which are detailed below.
-
-Step-by-step to build the program using clang++ and libc++ on linux:
- 1. Download the source code of netcdf-cxx, found at 'https://github.com/Unidata/netcdf-cxx4/releases/tag/v4.3.1' (make sure to download the release source code, as the master branch contains non-compilable code).
- 2. Edit the CMakeLists.txt file, by appending '-stdlib=libc++' to the `CMAKE_CXX_FLAGS` variable in line 430. This means line 430 should read: 
-    ```cmake 
-    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g -Wall -Wno-unused-variable -Wno-unused-parameter -stdlib=libc++")
-    ```
- 2. Build the source code with the following: 
-  ```sh 
-    mkdir build && cd build
-    cmake .. -DCMAKE_CXX_COMPILER=/usr/bin/clang++
-    make
-    ctest
-    sudo make install
-  ```
- 3. Now the code should compile through the standard steps described in the Compiling section.

advection/src/AdvectionKernel.h

@@ -0,0 +1,15 @@
+#ifndef ADVECTION_ADVECTIONKERNEL_H
+#define ADVECTION_ADVECTIONKERNEL_H
+
+#include <tuple>
+
+#include "Vel.h"
+
+#define DT 4000
+
+class AdvectionKernel {
+public:
+    virtual std::pair<double, double> advect(int time, double latitude, double longitude) const = 0;
+};
+
+#endif //ADVECTION_ADVECTIONKERNEL_H

advection/src/CMakeLists.txt

@@ -17,6 +17,9 @@ add_executable(Advection main.cpp
         UVGrid.h
         Vel.h
         Vel.cpp
+        AdvectionKernel.h
+        EulerAdvectionKernel.cpp
+        EulerAdvectionKernel.h
 )
 
 execute_process(

advection/src/EulerAdvectionKernel.cpp

@@ -0,0 +1,11 @@
+
+#include "EulerAdvectionKernel.h"
+
+using namespace std;
+
+EulerAdvectionKernel::EulerAdvectionKernel(std::shared_ptr<UVGrid> grid) { }
+
+std::pair<double, double> EulerAdvectionKernel::advect(int time, double latitude, double longitude) const {
+    auto [u,v] = (*grid)[time, latitude, longitude];
+    return {latitude+u*DT, longitude+v*DT};
+}

advection/src/EulerAdvectionKernel.h

@@ -0,0 +1,17 @@
+#ifndef ADVECTION_EULERADVECTIONKERNEL_H
+#define ADVECTION_EULERADVECTIONKERNEL_H
+
+#include "AdvectionKernel.h"
+#include "UVGrid.h"
+
+class EulerAdvectionKernel: public AdvectionKernel {
+private:
+    std::shared_ptr<UVGrid> grid;
+public:
+    explicit EulerAdvectionKernel(std::shared_ptr<UVGrid> grid);
+    std::pair<double, double> advect(int time, double latitude, double longitude) const override;
+
+};
+
+
+#endif //ADVECTION_EULERADVECTIONKERNEL_H

advection/src/interpolate.cpp

@@ -2,7 +2,7 @@
 
 using namespace std;
 
-Vel biadvection(const UVGrid &uvGrid, int time, double lat, double lon) {
+Vel bilinearinterpolation(const UVGrid &uvGrid, int time, double lat, double lon) {
     double latStep = uvGrid.latStep();
     double lonStep = uvGrid.lonStep();
     int timeStep = uvGrid.timeStep();
@@ -36,11 +36,11 @@ Vel biadvection(const UVGrid &uvGrid, int time, double lat, double lon) {
     return point;
 }
 
-vector<Vel> biadvection(const UVGrid &uvGrid, vector<tuple<int, double, double>> points) {
+vector<Vel> bilinearinterpolation(const UVGrid &uvGrid, vector<tuple<int, double, double>> points) {
     vector<Vel> result;
     result.reserve(points.size());
     for (auto [time, lat, lon]: points) {
-        result.push_back(biadvection(uvGrid, time, lat, lon));
+        result.push_back(bilinearinterpolation(uvGrid, time, lat, lon));
     }
 
     return result;

advection/src/interpolate.h

@@ -15,7 +15,7 @@
  * @param lon longitude of point
  * @return interpolated velocity
  */
-Vel biadvection(const UVGrid &uvGrid, int time, double lat, double lon);
+Vel bilinearinterpolation(const UVGrid &uvGrid, int time, double lat, double lon);
 
 /**
  * Helper function for bilnearly interpolating a vector of points
@@ -23,6 +23,6 @@ Vel biadvection(const UVGrid &uvGrid, int time, double lat, double lon);
  * @param points vector of points
  * @return interpolated velocities
  */
-std::vector<Vel> biadvection(const UVGrid &uvGrid, std::vector<std::tuple<int, double, double>> points);
+std::vector<Vel> bilinearinterpolation(const UVGrid &uvGrid, std::vector<std::tuple<int, double, double>> points);
 
 #endif //ADVECTION_INTERPOLATE_H

advection/src/main.cpp

@@ -6,8 +6,9 @@
 using namespace std;
 
 int main() {
-    UVGrid uvGrid;
+//    UVGrid uvGrid;
-    uvGrid.streamSlice(cout, 100);
+    std::shared_ptr<UVGrid> uvGrid = std::make_shared<UVGrid>();
+    uvGrid->streamSlice(cout, 100);
 
     int N = 10000000;  // Number of points
 
@@ -32,7 +33,7 @@ int main() {
 
     auto start = chrono::high_resolution_clock::now();
 
-    auto x = biadvection(uvGrid, points);
+    auto x = bilinearinterpolation(*uvGrid, points);
 
     auto stop = chrono::high_resolution_clock::now();