Merge pull request #633 from Bodo-inc/sahil/mpi-eg-quickstart

Add small MPI example to quickstart

Author: minrk

docs/source/_static/IPyParallel-MPI-Example.png

@@ -60,6 +60,30 @@ with ipp.Cluster() as rc:
 <source src="_static/basic.mp4"/>
 </video>
 
+You can similarly run MPI code using IPyParallel:
+
+```python
+import ipyparallel as ipp
+
+def mpi_example():
+    from mpi4py import MPI
+    comm = MPI.COMM_WORLD
+    return f"Hello World from rank {comm.Get_rank()}. total ranks={comm.Get_size()}"
+
+# request an MPI cluster with 4 engines
+with ipp.Cluster(engines='mpi', n=4) as rc:
+    # get a broadcast_view on the cluster which is best
+    # suited for MPI style computation
+    view = rc.broadcast_view()
+    # run the mpi_example function on all engines in parallel
+    r = view.apply_sync(mpi_example)
+    # Retrieve and print the result from the engines
+    print("\n".join(r))
+# at this point, the cluster processes have been shutdown
+```
+
+![IPyParallel-MPI-Example](./_static/IPyParallel-MPI-Example.png)
+
 Follow the [tutorial][] to learn more.
 
 [tutorial]: ./tutorial/index