{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "08425e2a",
   "metadata": {},
   "source": [
    "# gr015_smooth\n",
    "as described in:\n",
    " Modern Applied Statistics with S-Plus, 3rd Edition\n",
    " W.N. Venables and B.D. Ripley\n",
    " Chapter 9: Smooth Regression, Figure 9.1\n",
    "\n",
    "Example is a set of data on 133 observations of acceleration against time\n",
    "for a simulated motorcycle accident, taken from Silverman (1985). The data\n",
    "are read from motorcycle.dat (2 columns of floats)\n",
    "\n",
    "\n",
    "\n",
    "**Author:** Christian Stratowa, Vienna, Austria  \n",
    "<i><small>This notebook tutorial was automatically generated with <a href= \"https://github.com/root-project/root/blob/master/documentation/doxygen/converttonotebook.py\">ROOTBOOK-izer</a> from the macro found in the ROOT repository  on Tuesday, May 19, 2026 at 08:38 PM.</small></i>"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "8cd3a4b3",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "%%cpp -d\n",
    "#include \"TString.h\"\n",
    "#include \"TInterpreter.h\"\n",
    "#include <fstream>\n",
    "#include \"TH1.h\"\n",
    "#include \"TGraphSmooth.h\"\n",
    "#include \"TCanvas.h\"\n",
    "#include \"TSystem.h\"\n",
    "\n",
    "\n",
    "TCanvas *vC1;\n",
    "TGraph *grin, *grout;"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "2675d69b",
   "metadata": {},
   "source": [
    " Definition of a helper function: "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "0097ff48",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "%%cpp -d\n",
    "void DrawSmooth(Int_t pad, const char *title, const char *xt, const char *yt)\n",
    "{\n",
    "   vC1->cd(pad);\n",
    "   TH1F *vFrame = gPad->DrawFrame(0,-130,60,70);\n",
    "   vFrame->SetTitle(title);\n",
    "   vFrame->SetTitleSize(0.2);\n",
    "   vFrame->SetXTitle(xt);\n",
    "   vFrame->SetYTitle(yt);\n",
    "   grin->Draw(\"P\");\n",
    "   grout->DrawClone(\"LPX\");\n",
    "}"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "89d04f35",
   "metadata": {},
   "source": [
    "data taken from R library MASS: mcycle.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "78909859",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "TString dir = gROOT->GetTutorialDir();\n",
    "dir.Append(\"/visualisation/graphs/\");\n",
    "dir.ReplaceAll(\"/./\",\"/\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "e2843938",
   "metadata": {},
   "source": [
    "read file and add to fit object"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "453349bc",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "Double_t *x = new Double_t[133];\n",
    "Double_t *y = new Double_t[133];\n",
    "Double_t vX, vY;\n",
    "Int_t vNData = 0;\n",
    "ifstream vInput;\n",
    "vInput.open(Form(\"%smotorcycle.dat\",dir.Data()));\n",
    "while (1) {\n",
    "   vInput >> vX >> vY;\n",
    "   if (!vInput.good()) break;\n",
    "   x[vNData] = vX;\n",
    "   y[vNData] = vY;\n",
    "   vNData++;\n",
    "}//while\n",
    "vInput.close();\n",
    "grin = new TGraph(vNData,x,y);"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "5140e461",
   "metadata": {},
   "source": [
    "draw graph"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "97ed5c49",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "vC1 = new TCanvas(\"vC1\",\"Smooth Regression\",200,10,900,700);\n",
    "vC1->Divide(2,3);"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "9ae7fe86",
   "metadata": {},
   "source": [
    "Kernel Smoother\n",
    "create new kernel smoother and smooth data with bandwidth = 2.0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "c59ab862",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "TGraphSmooth *gs = new TGraphSmooth(\"normal\");\n",
    "grout = gs->SmoothKern(grin,\"normal\",2.0);\n",
    "DrawSmooth(1,\"Kernel Smoother: bandwidth = 2.0\",\"times\",\"accel\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "6cbe27e5",
   "metadata": {},
   "source": [
    "redraw ksmooth with bandwidth = 5.0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "1ad30cce",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "grout = gs->SmoothKern(grin,\"normal\",5.0);\n",
    "DrawSmooth(2,\"Kernel Smoother: bandwidth = 5.0\",\"\",\"\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "0cf41487",
   "metadata": {},
   "source": [
    "Lowess Smoother\n",
    "create new lowess smoother and smooth data with fraction f = 2/3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "4a8eaf58",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "grout = gs->SmoothLowess(grin,\"\",0.67);\n",
    "DrawSmooth(3,\"Lowess: f = 2/3\",\"\",\"\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "b9acb700",
   "metadata": {},
   "source": [
    "redraw lowess with fraction f = 0.2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "74fc0386",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "grout = gs->SmoothLowess(grin,\"\",0.2);\n",
    "DrawSmooth(4,\"Lowess: f = 0.2\",\"\",\"\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "9b9fb727",
   "metadata": {},
   "source": [
    "Super Smoother\n",
    "create new super smoother and smooth data with default bass = 0 and span = 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "a122c352",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "grout = gs->SmoothSuper(grin,\"\",0,0);\n",
    "DrawSmooth(5,\"Super Smoother: bass = 0\",\"\",\"\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "0c92e8dc",
   "metadata": {},
   "source": [
    "redraw supsmu with bass = 3 (smoother curve)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "9a8e2c84",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "grout = gs->SmoothSuper(grin,\"\",3);\n",
    "DrawSmooth(6,\"Super Smoother: bass = 3\",\"\",\"\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "acc8eef9",
   "metadata": {},
   "source": [
    "cleanup"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "8f25c7c5",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "delete [] x;\n",
    "delete [] y;\n",
    "delete gs;"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "7e815ee3",
   "metadata": {},
   "source": [
    "Draw all canvases "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "fa8e5621",
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "gROOT->GetListOfCanvases()->Draw()"
   ]
  }
 ],
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