{ "cells": [ { "cell_type": "markdown", "id": "c12e30ea", "metadata": {}, "source": [ "# Numerická integrace" ] }, { "cell_type": "markdown", "id": "d6464ffc", "metadata": {}, "source": [ "Naimportujeme si knihovny potřebné pro následující příklady:" ] }, { "cell_type": "code", "execution_count": 1, "id": "9479552b", "metadata": {}, "outputs": [], "source": [ "import numpy as np\n", "import matplotlib.pyplot as plt\n", "import scipy.integrate as integrate" ] }, { "cell_type": "markdown", "id": "e361df73", "metadata": {}, "source": [ "## Klasické kvadraturní vzorce\n", "- Máme ekvidistantní body $x_{i}$ a vypočteme $f_{i}(x_{i})$\n", "- V 1D aproximujeme integrál pomocí obdélníků/lichoběžníků\n", "- Přesnost je dána šířkou obdélníku\n", "\n", "### Newton–Cotesovy vzorce\n", "1. Obdélníkové pravidlo\n", "$$\n", "\\int_{x_{1}}^{x_{2}}f(x)\\,dx\\approx (x_{2}-x_{1})f\\left( \\dfrac{x_{1}+x_{2}}{2} \\right)\n", "$$\n", "\n", "2. Lichoběžníkové pravidlo\n", "$$\n", "\\int_{x_{1}}^{x_{2}}f(x)\\,dx\\approx (x_{2}-x_{1})\\dfrac{f(x_{1})+f(x_{2})}{2}\n", "$$\n", "\n", "3. Simpsonovo pravidlo\n", " - [Odvození](http://kfe.fjfi.cvut.cz/~vachal/edu/nme/cviceni/07_numint/DOCS/odvozeni_integrace_Lagrange.pdf)\n", "$$\n", "\\int_{x_{1}}^{x_{3}}f(x)\\,dx\\approx (x_{2}-x_{1})\\dfrac{f(x_{1})+4f(x_{2})+f(x_{3})}{3}\n", "$$\n" ] }, { "cell_type": "markdown", "id": "bd57fad7", "metadata": {}, "source": [ "