{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Choice of Nodes for Polynomial Interpolation\n",
    "\n",
    "Copyright (C) 2020 Andreas Kloeckner\n",
    "\n",
    "<details>\n",
    "<summary>MIT License</summary>\n",
    "Permission is hereby granted, free of charge, to any person obtaining a copy\n",
    "of this software and associated documentation files (the \"Software\"), to deal\n",
    "in the Software without restriction, including without limitation the rights\n",
    "to use, copy, modify, merge, publish, distribute, sublicense, and/or sell\n",
    "copies of the Software, and to permit persons to whom the Software is\n",
    "furnished to do so, subject to the following conditions:\n",
    "\n",
    "The above copyright notice and this permission notice shall be included in\n",
    "all copies or substantial portions of the Software.\n",
    "\n",
    "THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\n",
    "IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\n",
    "FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\n",
    "AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\n",
    "LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\n",
    "OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN\n",
    "THE SOFTWARE.\n",
    "</details>"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false,
    "jupyter": {
     "outputs_hidden": false
    }
   },
   "outputs": [],
   "source": [
    "%matplotlib qt5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false,
    "jupyter": {
     "outputs_hidden": false
    }
   },
   "outputs": [],
   "source": [
    "import numpy as np\n",
    "import numpy.linalg as la\n",
    "\n",
    "from matplotlib.pyplot import (\n",
    "    clf, plot, show, xlim, ylim,\n",
    "    get_current_fig_manager, gca, draw, connect)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Choose a function below:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false,
    "jupyter": {
     "outputs_hidden": false
    }
   },
   "outputs": [],
   "source": [
    "func = \"sin\"\n",
    "\n",
    "if func == \"sin\":\n",
    "    def f(x):\n",
    "        return np.sin(5*x)\n",
    "elif func == \"jump\":\n",
    "    def f(x):\n",
    "        result = 0*x\n",
    "        result.fill(-1)\n",
    "        result[x > 0] = 1\n",
    "        return result\n",
    "elif func == \"runge\":\n",
    "    def f(x):\n",
    "        return 1/(1+25*x**2)\n",
    "else:\n",
    "    raise RuntimeError(\"unknown function '%s'\" % func)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Run this cell to play with the node placement toy:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false,
    "jupyter": {
     "outputs_hidden": false
    }
   },
   "outputs": [
    {
     "data": {
      "image/png": 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\n",
      "text/plain": [
       "<Figure size 432x288 with 1 Axes>"
      ]
     },
     "metadata": {
      "needs_background": "light"
     },
     "output_type": "display_data"
    }
   ],
   "source": [
    "#keep\n",
    "x_points = []\n",
    "y_points = []\n",
    "deg = [1]\n",
    "\n",
    "def update_plot():\n",
    "    clf()\n",
    "    xlim([-1, 1])\n",
    "    ylim([-1.5, 1.5])\n",
    "    gca().set_autoscale_on(False)\n",
    "    plot(x_points, y_points, 'o')\n",
    "\n",
    "    x = np.linspace(-1, 1, 500)\n",
    "    plot(x, f(x), \"--\")\n",
    "\n",
    "    if len(x_points) >= deg[0]+1:\n",
    "        eval_points = np.linspace(-1, 1, 500)\n",
    "        poly = np.poly1d(np.polyfit(\n",
    "            np.array(x_points),\n",
    "            np.array(y_points), deg[0]))\n",
    "        plot(eval_points, poly(eval_points), \"-\")\n",
    "\n",
    "\n",
    "def click(event):\n",
    "    \"\"\"If the left mouse button is pressed: draw a little square. \"\"\"\n",
    "    tb = get_current_fig_manager().toolbar\n",
    "    if event.button == 1 and event.inaxes and tb.mode == '':\n",
    "        x_points.append(event.xdata)\n",
    "        x_ary = np.array([event.xdata])\n",
    "        y_ary = f(x_ary)\n",
    "        y_points.append(y_ary[0])\n",
    "\n",
    "    if event.button == 3 and event.inaxes and tb.mode == '':\n",
    "        if len(x_points) >= deg[0]+2:\n",
    "            deg[0] += 1\n",
    "\n",
    "    update_plot()\n",
    "    draw()\n",
    "\n",
    "update_plot()\n",
    "connect('button_press_event', click)\n",
    "show()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false,
    "jupyter": {
     "outputs_hidden": false
    }
   },
   "outputs": [],
   "source": []
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true,
    "jupyter": {
     "outputs_hidden": true
    }
   },
   "outputs": [],
   "source": []
  }
 ],
 "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": "3.8.3"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 4
}