From 13f3b9c578d5aae7d6c510525f17c9292792a2aa Mon Sep 17 00:00:00 2001 From: 318b38cbf16538baf6f4efa72de94b90 <318b38cbf16538baf6f4efa72de94b90@app-learninglab.inria.fr> Date: Mon, 17 Apr 2023 16:04:20 +0000 Subject: [PATCH] ok --- module2/exo1/toy_notebook_fr.ipynb | 149 ++++++++++++++++++++++++++--- 1 file changed, 134 insertions(+), 15 deletions(-) diff --git a/module2/exo1/toy_notebook_fr.ipynb b/module2/exo1/toy_notebook_fr.ipynb index 0bbbe37..dbd72d3 100644 --- a/module2/exo1/toy_notebook_fr.ipynb +++ b/module2/exo1/toy_notebook_fr.ipynb @@ -1,25 +1,144 @@ { - "cells": [], + "cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# À propos du calcul de $\\pi$" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## En demandant à la lib maths\n", + "Mon ordinateur m'indique que $\\pi$ vaut *approximativement*" + ] + }, + { + "cell_type": "code", + "execution_count": 15, + "metadata": { + "scrolled": true + }, + "outputs": [ + { + "ename": "ERROR", + "evalue": "Error in parse(text = x, srcfile = src): :1:6: unexpected symbol\n1: from math\n ^\n", + "output_type": "error", + "traceback": [ + "Error in parse(text = x, srcfile = src): :1:6: unexpected symbol\n1: from math\n ^\nTraceback:\n" + ] + } + ], + "source": [ + "from math import *\n", + "print(pi)" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## En utilisant la méthode des aiguilles de Buffon\n", + "Mais calculé avec la __méthode__ des [aiguilles de Buffon](https://fr.wikipedia.org/wiki/Aiguille_de_Buffon), on obtiendrait comme __approximation__ :" + ] + }, + { + "cell_type": "code", + "execution_count": 16, + "metadata": {}, + "outputs": [ + { + "ename": "ERROR", + "evalue": "Error in parse(text = x, srcfile = src): :1:8: unexpected symbol\n1: import numpy\n ^\n", + "output_type": "error", + "traceback": [ + "Error in parse(text = x, srcfile = src): :1:8: unexpected symbol\n1: import numpy\n ^\nTraceback:\n" + ] + } + ], + "source": [ + "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)" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## 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 $P[X^2+Y^2\\leq 1] = \\pi/4$ (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 :" + ] + }, + { + "cell_type": "code", + "execution_count": 18, + "metadata": {}, + "outputs": [ + { + "ename": "ERROR", + "evalue": "Error in parse(text = x, srcfile = src): :1:1: unexpected input\n1: %matplotlib inline \n ^\n", + "output_type": "error", + "traceback": [ + "Error in parse(text = x, srcfile = src): :1:1: unexpected input\n1: %matplotlib inline \n ^\nTraceback:\n" + ] + } + ], + "source": [ + "%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')" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "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 :" + ] + }, + { + "cell_type": "code", + "execution_count": null, + "metadata": {}, + "outputs": [], + "source": [ + "4*np.mean(accept)" + ] + } + ], "metadata": { "kernelspec": { - "display_name": "Python 3", - "language": "python", - "name": "python3" + "display_name": "R", + "language": "R", + "name": "ir" }, "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 3 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython3", - "version": "3.6.3" + "codemirror_mode": "r", + "file_extension": ".r", + "mimetype": "text/x-r-source", + "name": "R", + "pygments_lexer": "r", + "version": "3.4.1" } }, "nbformat": 4, "nbformat_minor": 2 } - -- 2.18.1