SO14184621.ipynb

{
 "metadata": {
  "name": "SO14184621"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "For SO Question [14184621](http://stackoverflow.com/questions/14184621)"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Connect to the cluster"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from IPython.parallel import Client\n",
      "rc = Client()\n",
      "lview = rc.load_balanced_view()\n",
      "dv = rc[:]"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Define a magic that runs a cell locally *and* remotely"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def pxlocal(line, cell):\n",
      "    ip = get_ipython()\n",
      "    ip.run_cell_magic(\"px\", line, cell)\n",
      "    ip.run_cell(cell)\n",
      "ip.register_magic_function(pxlocal, \"cell\")    "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 2
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Use the magic to define a class interactively everywhere (including local)"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%%pxlocal\n",
      "class MyClass(object):\n",
      "    def __init__(self, parameter):\n",
      "        self.parameter = parameter\n",
      "\n",
      "    def update_something(self, some_data):\n",
      "       # do something smart here with some_data & internal state\n",
      "        self.parameter = some_data\n",
      "    \n",
      "    def compute_something(self, other_data):\n",
      "        # do something smart here with other data & internal state\n",
      "        return self.parameter * other_data"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Run some tasks"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def process(obj, some_data, other_data):\n",
      "    obj.update_something(some_data)\n",
      "    return obj.compute_something(other_data)\n",
      "\n",
      "tasks = []\n",
      "some_instances = [MyClass(i) for i in range(5)]\n",
      "data_source_1 = range(1,4)\n",
      "data_source_2 = range(4,1,-1)\n",
      "for obj in some_instances:\n",
      "   for some_data in data_source_1:\n",
      "        for other_data in data_source_2:\n",
      "            ar = lview.apply_async(process, obj, some_data, other_data)\n",
      "            tasks.append(ar)\n",
      "\n",
      "# wait for computation to end\n",
      "results = [ar.get() for ar in tasks] "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "results[:18]"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 5,
       "text": [
        "[4, 3, 2, 8, 6, 4, 12, 9, 6, 4, 3, 2, 8, 6, 4, 12, 9, 6]"
       ]
      }
     ],
     "prompt_number": 5
    }
   ],
   "metadata": {}
  }
 ]
}