- everything works

experiment.cpp

@@ -75,7 +75,7 @@ int main(int argc, char** argv)
   auto dt = dx / 8;
 
   double time = 0;
-  double Tfinal = 0.2;
+  double Tfinal = 0.20;
   std::size_t iter = 0;
   std::size_t max_iter = 100000;
 
@@ -84,21 +84,25 @@ int main(int argc, char** argv)
 
     if (world_rank == 0) {
       for (std::size_t i = 0; i < nhalo; ++i) {
-        halo_send[i] = data[ncell - nhalo + i];
+        halo_send[i] = static_cast<send_type>(data[ncell - nhalo + i]);
       }
       MPI_Request send_handle;
       MPI_Request recv_handle;
       MPI_Irecv(halo_recv.data(), nhalo, mpi_type, 1, 0, MPI_COMM_WORLD, &recv_handle);
-      MPI_Isend(halo_send.data(), nhalo, mpi_type, 1, 0, MPI_COMM_WORLD, &send_handle);
+      MPI_Isend(halo_send.data(), nhalo, mpi_type, 1, 1, MPI_COMM_WORLD, &send_handle);
+      MPI_Wait(&send_handle, MPI_STATUS_IGNORE);
+      MPI_Wait(&recv_handle, MPI_STATUS_IGNORE);
 
     } else {
       for (std::size_t i = 0; i < nhalo; ++i) {
-        halo_send[i] = data[i];
+        halo_send[i] = static_cast<send_type>(data[i]);
       }
       MPI_Request send_handle;
       MPI_Request recv_handle;
-      MPI_Irecv(halo_recv.data(), nhalo, mpi_type, 0, 0, MPI_COMM_WORLD, &recv_handle);
+      MPI_Irecv(halo_recv.data(), nhalo, mpi_type, 0, 1, MPI_COMM_WORLD, &recv_handle);
       MPI_Isend(halo_send.data(), nhalo, mpi_type, 0, 0, MPI_COMM_WORLD, &send_handle);
+      MPI_Wait(&send_handle, MPI_STATUS_IGNORE);
+      MPI_Wait(&recv_handle, MPI_STATUS_IGNORE);
     }
 
     for (std::size_t i = 1; i < ncell - 1; ++i) {
@@ -109,12 +113,17 @@ int main(int argc, char** argv)
       std::size_t ix = ncell - 1;
       tmp[ix]
           = data[ix]
-          + dt / dx * (numflux(data[ix - 1], data[ix]) - numflux(data[ix], halo_recv[nhalo - 1]));
+          + dt / dx * (numflux(data[ix - 1], data[ix]) - numflux(data[ix], halo_recv[0]));
     } else {
       std::size_t ix = 0;
       tmp[ix]
           = data[ix]
-          + dt / dx * (numflux(data[ix - 1], data[ix]) - numflux(data[ix], halo_recv[0]));
+          + dt / dx * (numflux(halo_recv[nhalo - 1], data[ix]) - numflux(data[ix], data[ix + 1]));
+
+      ix = ncell - 1;
+      tmp[ix]
+          = data[ix]
+          + dt / dx * (numflux(data[ix - 1], data[ix]) - numflux(data[ix], data[ix]));
     }
 
     for (std::size_t i = 0; i < ncell; ++i) {
@@ -123,8 +132,10 @@ int main(int argc, char** argv)
 
     time += dt;
     ++iter;
+    if (world_rank == 0) {
       std::cout << "iter = " << iter << "\ttime = " << time << "\tdt = " << dt << "\n";
     }
+  }
 
   auto const final_filename = "data_" + std::to_string(world_rank) + ".final.txt";
   std::ofstream final_file(final_filename);