From bd1808cc202b9172e4487a3df8c5e6e74ac1069a Mon Sep 17 00:00:00 2001 From: 6f892419cc99326ee525ed439d8ff5df <6f892419cc99326ee525ed439d8ff5df@app-learninglab.inria.fr> Date: Sat, 27 Feb 2021 21:52:00 +0000 Subject: [PATCH] 9 --- module2/exo1/toy_notebook_fr.ipynb | 52 ++++++++++++++++-------------- 1 file changed, 27 insertions(+), 25 deletions(-) diff --git a/module2/exo1/toy_notebook_fr.ipynb b/module2/exo1/toy_notebook_fr.ipynb index fad33ff..81be118 100644 --- a/module2/exo1/toy_notebook_fr.ipynb +++ b/module2/exo1/toy_notebook_fr.ipynb @@ -10,8 +10,7 @@ "Mon ordinateur m'indique que $\\pi$ vaut *approximativement*\n", "\n", "\n", - "In \\[1]:\n", - ">from math import *\n", + "In \\[1]:>from math import *\n", ">print (pi)\n", " \n", "3.141592653589793\n", @@ -23,14 +22,15 @@ "\n", "\n", "In \\[2]:\n", - "import numpy as np\n", - "np.random.seed(seed=42)\n", - "N = 10000\n", - "x = np.random.uniform(size=N, low=0, high=1)\n", - "theta = np.random.uniform(size=N, low=0, high=pi/2)\n", - "2/(sum((x+np.sin(theta))>1)/N)\n", + ">import numpy as np\n", + ">np.random.seed(seed=42)\n", + ">N = 10000\n", + ">x = np.random.uniform(size=N, low=0, high=1)\n", + ">theta = np.random.uniform(size=N, low=0, high=pi/2)\n", + ">2/(sum((x+np.sin(theta))>1)/N)\n", " \n", - "3.1289111389236548\n", + "Out\\[2]: 3.1289111389236548\n", + "\n", "\n", "## 1.3 Avec un argument \"fréquentiel\" de surface\n", "Sinon, une méthode plus simple à comprendre et ne faisant pas intervenir d'appel à la fonction sinus se base sur le fait que si $X\\sim U(0,1)$ et $Y\\sim U(0,1)$ alors $P[X^2+Y^2\\leq1] = \\pi/4$ (voir [méthode de Monte Carlo sur Wikipedia](https://fr.wikipedia.org/wiki/M%C3%A9thode_de_Monte-Carlo#D%C3%A9termination_de_la_valeur_de_%CF%80)). Le code suivant illustre ce fait :\n", @@ -38,29 +38,31 @@ "\n", "In \\[3]:\n", "\n", - "%matplotlib inline\n", - "import matplotlib.pyplot as plt\n", + ">%matplotlib inline\n", + ">import matplotlib.pyplot as plt\n", + "\n", + ">np.random.seed(seed=42)\n", + ">N = 1000\n", + ">x = np.random.uniform(size=N, low=0, high=1)\n", + ">y = np.random.uniform(size=N, low=0, high=1)\n", + "\n", + ">accept = (x*x+y*y) <=1\n", + ">reject = np.logical_not(accept)\n", + "\n", + ">fig, ax = plt.subplots(1)\n", + ">ax.scatter(x[accept], y [accept], c='b', alpha=0.2, edgecolor=None)\n", + ">ax.scatter(x[reject], y [reject], c='r', alpha=0.2, edgecolor=None)\n", + ">ax.set_aspect('equal')\n", "\n", - "np.random.seed(seed=42)\n", - "N = 1000\n", - "x = np.random.uniform(size=N, low=0, high=1)\n", - "y = np.random.uniform(size=N, low=0, high=1)\n", "\n", - "accept = (x*x+y*y) <=1\n", - "reject = np.logical_not(accept)\n", "\n", - "fig, ax = plt.subplots(1)\n", - "ax.scatter(x[accept], y [accept], c='b', alpha=0.2, edgecolor=None)\n", - "ax.scatter(x[reject], y [reject], c='r', alpha=0.2, edgecolor=None)\n", - "ax.set_aspect('equal')\n", + ">Il est alors aisé d'obtenir une approximation (pas terrible) de $\\pi$ en comptant combien de fois, en moyenne, $X^2 + Y^2$ est inférieur à 1 :\n", "\n", - "Il est alors aisé d'obtenir une approximation (pas terrible) de $\\pi$ en comptant combien de fois, en moyenne, $X^2 + Y^2$ est inférieur à 1 :\n", "\n", + "In \\[4]: 4*np.mean(accept)\n", "\n", - "In \\[4]:\n", + "Out\\[4]: 3.1120000000000001\n", "\n", - "4*np.mean(accept)\n", - "3.1120000000000001\n", "\n" ] }, -- 2.18.1