title: Sending and receiving 2D array over MPI
body: <p>The issue I am trying to resolve is the following:</p>
  
  <p>The C++ serial code I have computes across a large 2D matrix. To optimize this process, I wish to split this large 2D matrix and run on 4 nodes (say) using MPI. The only communication that occurs between nodes is the sharing of edge values at the end of each time step. Every node shares the edge array data, A[i][j], with its neighbor. </p>
  
  <p>Based on reading about MPI, I have the following scheme to be implemented.</p>
  
  <pre><code>if (myrank == 0)
  {
   for (i= 0 to x)
   for (y= 0 to y)
   {
    C++ CODE IMPLEMENTATION 
    .... 
    MPI_SEND(A[x][0], A[x][1], A[x][2], Destination= 1.....)
    MPI_RECEIVE(B[0][0], B[0][1]......Sender = 1.....)
    MPI_BARRIER
  }
  
  if (myrank == 1)
  {
  for (i = x+1 to xx)
  for (y = 0 to y)
  {
   C++ CODE IMPLEMENTATION
   ....
   MPI_SEND(B[x][0], B[x][1], B[x][2], Destination= 0.....)
   MPI_RECEIVE(A[0][0], A[0][1]......Sender = 1.....)
   MPI BARRIER
  }
  </code></pre>
  
  <p>I wanted to know if my approach is correct and also would appreciate any guidance on other MPI functions too look into for implementation. </p>
  
  <p>Thanks,
  Ashwin.</p>