{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# **A propos du calcul de $\\pi$**" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## **En demandant à la lib maths**" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Mon ordinateur m'indique que $\\pi$ vaut *approximativement*" ] }, { "cell_type": "code", "execution_count": 7, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "3.141592653589793\n" ] } ], "source": [ "from math import pi\n", "print (pi)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## **En utilisant la méthode des aiguilles de Buffon**" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "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": 10, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "3.128911138923655" ] }, "execution_count": 10, "metadata": {}, "output_type": "execute_result" } ], "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**" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "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] = \\frac{pi}{4}" ] } ], "metadata": { "kernelspec": { "display_name": "Python 3", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.6.4" } }, "nbformat": 4, "nbformat_minor": 2 }