+ initial commit

.gitignore

+data_*
+experiment

experiment.cpp

+#include <cmath>
+#include <fstream>
+#include <mpi.h>
+#include <stdio.h>
+#include <vector>
+
+double index_to_x(std::size_t i, double xl, double dx)
+{
+  return xl + i * dx;
+}
+
+int main(int argc, char** argv)
+{
+  // Initialize the MPI environment
+  MPI_Init(NULL, NULL);
+
+  // Get the number of processes
+  int world_size;
+  MPI_Comm_size(MPI_COMM_WORLD, &world_size);
+
+  std::size_t ncell = 10'000;
+  std::size_t nhalo = ncell / 2;
+  double xl = -2.0;
+  double xr = 2.0;
+  double dx = (xr - xl) / (2 * ncell);
+  double lxl = -2.0;
+  double lxr = 0.0;
+  double lxc = -1.0;
+  double rxl = 0.0;
+  double rxr = 2.0;
+  double rxc = 1.0;
+
+  // Get the rank of the process
+  int world_rank;
+  MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
+
+  std::vector<double> data(ncell);
+  std::vector<double> halo(nhalo);
+
+  if (world_rank == 0) {
+    for (std::size_t i = 0; i < ncell; ++i) {
+      auto x = index_to_x(i, lxl, dx);
+      data[i] = 1 + std::exp(-10 * (x - lxc) * (x - lxc));
+    }
+  } else {
+    for (std::size_t i = 0; i < ncell; ++i) {
+      auto x = index_to_x(i, rxl, dx);
+      data[i] = 1 + std::exp(-10 * (x - rxc) * (x - rxc));
+    }
+  }
+
+  auto const filename = "data_" + std::to_string(world_rank) + ".txt";
+  std::ofstream file(filename);
+  for (std::size_t i = 0; i < ncell; ++i) {
+    file << index_to_x(i, xl, dx) << " " << data[i] << "\n";
+  }
+
+  // Finalize the MPI environment.
+  MPI_Finalize();
+}

makefile

+experiment: experiment.cpp
+	mpicxx -std=c++20 -o experiment experiment.cpp

plot.py

+#!/usr/bin/env python3
+
+import argparse
+import matplotlib.pyplot as plt
+import csv
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-i', '--input', help='input file')
+    parser.add_argument('-o', '--output', help='output file')
+
+    args = parser.parse_args()
+    input_file = args.input
+    output_file = args.output
+
+
+    with open(input_file, 'r') as f:
+        plots = csv.reader(f, delimiter=' ')
+        x = []
+        y = []
+        for row in plots:
+            x.append(float(row[0]))
+            y.append(float(row[1]))
+
+
+
+    plt.plot(x, y, label=input_file)
+    plt.xlabel('x')
+    plt.ylabel('y')
+    plt.yscale("linear")
+    #plt.tick_params(bottom = False)
+    #plt.tick_params(left= False)
+    #plt.tick_params(labelbottom=False)
+    #plt.tick_params(labelleft=False)
+    ax = plt.gca()
+    ax.set_aspect('equal', adjustable='box')
+    print('Saving plot to {}'.format(output_file))
+    plt.savefig(output_file)
+