Compute PI

{
 "metadata": {
  "name": ""
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from IPython.parallel import Client\n",
      "from mpi4py import MPI\n",
      "c = Client(profile='mpi') # cluster has been started with 4 procs\n",
      "view = c[:]\n",
      "view.activate()\n",
      "view.block = True\n",
      "print c.ids"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[0, 1, 2, 3]\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%px import numpy as np\n",
      "%px from mpi4py import MPI\n",
      "%px from compute_pi import compute_pi\n",
      "%px comm = MPI.COMM_WORLD\n",
      "%px size = comm.Get_size()\n",
      "%px rank = comm.Get_rank()\n",
      "view['rank']"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 2,
       "text": [
        "[3, 1, 2, 0]"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%px mypi = compute_pi(rank, size, 100, comm)\n",
      "%px pi = np.zeros( (1,), dtype='d')\n",
      "%px comm.Allreduce([np.array(mypi),MPI.DOUBLE],[pi,MPI.DOUBLE],MPI.SUM)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "print view['mypi']\n",
      "print view['pi']"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[0.7778741525634219, 0.7879260283629755, 0.7829244650957667, 0.7928763409009609]\n",
        "[array([ 3.14160099]), array([ 3.14160099]), array([ 3.14160099]), array([ 3.14160099])]\n"
       ]
      }
     ],
     "prompt_number": 4
    }
   ],
   "metadata": {}
  }
 ]
}