Monty Hall

.gitignore

.ipynb_checkpoints/*

Monty Hall Simulation.markdown

Just an example iPython notebook

notebook.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "import random as r\n",
    "import math\n",
    "\n",
    "# PARAMETERS\n",
    "N = 100000\n",
    "\n",
    "# Select a random in between 1 and 3\n",
    "\n",
    "def randDoor():\n",
    "    return 1 + int(3*r.random())\n",
    "\n",
    "def randOtherDoor(g, p):\n",
    "    if (g == p):\n",
    "        r = randDoor()\n",
    "        while (r == g):\n",
    "            r = randDoor()\n",
    "        return r\n",
    "    else:\n",
    "        return 6 - g - p\n",
    "\n",
    "# Door you select if you switch your guess, given that you guessed\n",
    "# door g and the prize is behind door p where the host reveals\n",
    "# randOtherDoor(g, p)\n",
    "def switch(g, p):\n",
    "    o = randOtherDoor(g, p)\n",
    "    return 6 - g - o"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Strategy 1 wins = 33298, Strategy 2 wins = 66702\n"
     ]
    }
   ],
   "source": [
    "strategy1wins = 0\n",
    "strategy2wins = 0\n",
    "for i in range(0,N):\n",
    "    prize = randDoor()\n",
    "    guess = randDoor()\n",
    "    reveal = randOtherDoor(guess, prize)\n",
    "    otherdoorleft = 6 - reveal - guess\n",
    "    if (prize == guess):\n",
    "        strategy1wins += 1\n",
    "    if (prize == otherdoorleft):\n",
    "        strategy2wins += 1\n",
    "\n",
    "print \"Strategy 1 wins = {0:d}, Strategy 2 wins = {1:d}\".format(strategy1wins, strategy2wins)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 49,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[33480, 33291, 33229]\n"
     ]
    }
   ],
   "source": [
    "prizes = map((lambda(x) : randDoor()), range(0,N))\n",
    "# Print counts of times prize is behind each door\n",
    "print map ((lambda(y): len(filter((lambda(x): x == y), prizes))),[1,2,3])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 55,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Frequency strategy is correct = 0.33:\n"
     ]
    }
   ],
   "source": [
    "guesses = map((lambda(x) : randDoor()), range(0,N))\n",
    "print \"Frequency strategy is correct = {0:.2f}:\".format(float(len(filter((lambda(x) : guesses[x] == prize[x]), range(0,N))))/N)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 56,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Frequency strategy is correct = 0.67:\n"
     ]
    }
   ],
   "source": [
    "strategy = map (lambda(x): switch(guess[x], prize[x]), range(0,N))\n",
    "print \"Frequency strategy is correct = {0:.2f}:\".format(float(len(filter((lambda(x) : strategy[x] == prize[x]), range(0,N))))/N)"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 2",
   "language": "python",
   "name": "python2"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 2
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython2",
   "version": "2.7.10"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 0
}