{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "df9c6f2b",
   "metadata": {},
   "source": [
    "# rf514_RooCustomizer\n",
    "Using the RooCustomizer to create multiple PDFs that share a lot of properties, but have unique parameters for each category.\n",
    "As an extra complication, some of the new parameters need to be functions\n",
    "of a mass parameter.\n",
    "\n",
    "\n",
    "\n",
    "\n",
    "**Author:** Stephan Hageboeck, CERN  \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 08:32 PM.</small></i>"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "6a7b01df",
   "metadata": {},
   "source": [
    "Define a proto model that will be used as the template for each category\n",
    "---------------------------------------------------------------------------"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "afa692b3",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:47.916808Z",
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     "shell.execute_reply": "2026-05-19T20:32:48.483303Z"
    }
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[#0] WARNING:InputArguments -- The parameter 'sigmaG' with range [-inf, inf] of the RooGaussian 'gauss' exceeds the safe range of (0, inf). Advise to limit its range.\n",
      "The proto model before customisation:\n",
      "0x7f5d86d75218 RooAddPdf::model = 750.5/1 [Auto,Clean] \n",
      "  0x7f5d86d73bc0/V- RooGaussian::gauss = 0 [Auto,Dirty] \n",
      "    0x7f5d86d73008/V- RooRealVar::Energy = 1500\n",
      "    0x7f5d86d733f0/V- RooRealVar::meanG = 100\n",
      "    0x7f5d86d737d8/V- RooRealVar::sigmaG = 3\n",
      "  0x7f5d86d74a48/V- RooRealVar::yieldSig = 1\n",
      "  0x7f5d86d74500/V- RooPolynomial::linear = 1501 [Auto,Dirty] \n",
      "    0x7f5d86d73008/V- RooRealVar::Energy = 1500\n",
      "    0x7f5d86d74118/V- RooRealVar::pol1 = 1\n",
      "  0x7f5d86d74e30/V- RooRealVar::yieldBkg = 1\n"
     ]
    }
   ],
   "source": [
    "RooRealVar E(\"Energy\",\"Energy\",0,3000);\n",
    "\n",
    "RooRealVar meanG(\"meanG\",\"meanG\", 100., 0., 3000.);\n",
    "RooRealVar sigmaG(\"sigmaG\",\"sigmaG\", 3.);\n",
    "RooGaussian gauss(\"gauss\", \"gauss\", E, meanG, sigmaG);\n",
    "\n",
    "RooRealVar pol1(\"pol1\", \"Constant of the polynomial\", 1, -10, 10);\n",
    "RooPolynomial linear(\"linear\", \"linear\", E, pol1);\n",
    "\n",
    "RooRealVar yieldSig(\"yieldSig\", \"yieldSig\", 1, 0, 1.E4);\n",
    "RooRealVar yieldBkg(\"yieldBkg\", \"yieldBkg\", 1, 0, 1.E4);\n",
    "\n",
    "RooAddPdf model(\"model\", \"S + B model\",\n",
    "    RooArgList(gauss,linear),\n",
    "    RooArgList(yieldSig, yieldBkg));\n",
    "\n",
    "std::cout << \"The proto model before customisation:\" << std::endl;\n",
    "model.Print(\"T\"); // \"T\" prints the model as a tree"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "c563ce92",
   "metadata": {},
   "source": [
    "Build the categories"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "feebd945",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:48.485446Z",
     "iopub.status.busy": "2026-05-19T20:32:48.485327Z",
     "iopub.status.idle": "2026-05-19T20:32:48.714855Z",
     "shell.execute_reply": "2026-05-19T20:32:48.697374Z"
    }
   },
   "outputs": [
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "input_line_53:2:2: warning: 'sample' shadows a declaration with the same name in the 'std' namespace; use '::sample' to reference this declaration\n",
      " RooCategory sample(\"sample\",\"sample\");\n",
      " ^\n"
     ]
    }
   ],
   "source": [
    "RooCategory sample(\"sample\",\"sample\");\n",
    "sample[\"Sample1\"] = 1;\n",
    "sample[\"Sample2\"] = 2;\n",
    "sample[\"Sample3\"] = 3;"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "69baf675",
   "metadata": {},
   "source": [
    "Start to customise the proto model that was defined above.\n",
    "---------------------------------------------------------------------------"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "67b0afa5",
   "metadata": {},
   "source": [
    "We need two sets for bookkeeping of PDF nodes:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "0e030827",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:48.716620Z",
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     "shell.execute_reply": "2026-05-19T20:32:48.921751Z"
    }
   },
   "outputs": [],
   "source": [
    "RooArgSet newLeaves;           // This set collects leaves that are created in the process.\n",
    "RooArgSet allCustomiserNodes; // This set lists leaves that have been used in a replacement operation."
   ]
  },
  {
   "cell_type": "markdown",
   "id": "0480a786",
   "metadata": {},
   "source": [
    "1. Each sample should have its own mean for the gaussian\n",
    "The customiser will make copies of `meanG` for each category.\n",
    "These will all appear in the set `newLeaves`, which will own the new nodes."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "d4fec911",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:48.923989Z",
     "iopub.status.busy": "2026-05-19T20:32:48.923870Z",
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     "shell.execute_reply": "2026-05-19T20:32:49.132623Z"
    }
   },
   "outputs": [
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "input_line_55:2:28: error: reference to 'sample' is ambiguous\n",
      " RooCustomizer cust(model, sample, newLeaves, &allCustomiserNodes);\n",
      "                           ^\n",
      "input_line_53:2:14: note: candidate found by name lookup is 'sample'\n",
      " RooCategory sample(\"sample\",\"sample\");\n",
      "             ^\n",
      "/usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/stl_algo.h:5826:5: note: candidate found by name lookup is 'std::sample'\n",
      "    sample(_PopulationIterator __first, _PopulationIterator __last,\n",
      "    ^\n",
      "input_line_55:3:22: error: reference to 'sample' is ambiguous\n",
      "cust.splitArg(meanG, sample);\n",
      "                     ^\n",
      "input_line_53:2:14: note: candidate found by name lookup is 'sample'\n",
      " RooCategory sample(\"sample\",\"sample\");\n",
      "             ^\n",
      "/usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/stl_algo.h:5826:5: note: candidate found by name lookup is 'std::sample'\n",
      "    sample(_PopulationIterator __first, _PopulationIterator __last,\n",
      "    ^\n"
     ]
    }
   ],
   "source": [
    "RooCustomizer cust(model, sample, newLeaves, &allCustomiserNodes);\n",
    "cust.splitArg(meanG, sample);"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "7408cad4",
   "metadata": {},
   "source": [
    "2. Each sample should have its own signal yield, but there is an extra complication:\n",
    "We need the yields 1 and 2 to be a function of the variable \"mass\".\n",
    "For this, we pre-define nodes with exactly the names that the customiser would have created automatically,\n",
    "that is, \"<nodeName>_<categoryName>\", and we register them in the set of customiser nodes.\n",
    "The customiser will pick them up instead of creating new ones.\n",
    "If we don't provide one (e.g. for \"yieldSig_Sample3\"), it will be created automatically by cloning `yieldSig`."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "8ceb1cf2",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:49.134599Z",
     "iopub.status.busy": "2026-05-19T20:32:49.134483Z",
     "iopub.status.idle": "2026-05-19T20:32:49.343130Z",
     "shell.execute_reply": "2026-05-19T20:32:49.342497Z"
    }
   },
   "outputs": [],
   "source": [
    "RooRealVar mass(\"M\", \"M\", 1, 0, 12000);\n",
    "RooFormulaVar yield1(\"yieldSig_Sample1\", \"Signal yield in the first sample\", \"M/3.360779\", mass);\n",
    "RooFormulaVar yield2(\"yieldSig_Sample2\", \"Signal yield in the second sample\", \"M/2\", mass);\n",
    "allCustomiserNodes.add(yield1);\n",
    "allCustomiserNodes.add(yield2);"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "48bb7e63",
   "metadata": {},
   "source": [
    "Instruct the customiser to replace all yieldSig nodes for each sample:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "7cc75a96",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:49.344955Z",
     "iopub.status.busy": "2026-05-19T20:32:49.344837Z",
     "iopub.status.idle": "2026-05-19T20:32:49.553700Z",
     "shell.execute_reply": "2026-05-19T20:32:49.553137Z"
    }
   },
   "outputs": [
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "input_line_69:2:26: error: reference to 'sample' is ambiguous\n",
      " cust.splitArg(yieldSig, sample);\n",
      "                         ^\n",
      "input_line_53:2:14: note: candidate found by name lookup is 'sample'\n",
      " RooCategory sample(\"sample\",\"sample\");\n",
      "             ^\n",
      "/usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/stl_algo.h:5826:5: note: candidate found by name lookup is 'std::sample'\n",
      "    sample(_PopulationIterator __first, _PopulationIterator __last,\n",
      "    ^\n"
     ]
    }
   ],
   "source": [
    "cust.splitArg(yieldSig, sample);"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "053bb15a",
   "metadata": {},
   "source": [
    "Now we can start building the PDFs for all categories:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "e35eb14e",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:49.555257Z",
     "iopub.status.busy": "2026-05-19T20:32:49.555147Z",
     "iopub.status.idle": "2026-05-19T20:32:49.760831Z",
     "shell.execute_reply": "2026-05-19T20:32:49.760277Z"
    }
   },
   "outputs": [
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "input_line_70:2:14: error: cannot deduce 'auto' from unknown expression\n",
      " auto pdf1 = cust.build(\"Sample1\");\n",
      "             ^\n"
     ]
    }
   ],
   "source": [
    "auto pdf1 = cust.build(\"Sample1\");\n",
    "auto pdf2 = cust.build(\"Sample2\");\n",
    "auto pdf3 = cust.build(\"Sample3\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "58fb3d42",
   "metadata": {},
   "source": [
    "And we inspect the two PDFs"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "a99ae4d1",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:49.762243Z",
     "iopub.status.busy": "2026-05-19T20:32:49.762129Z",
     "iopub.status.idle": "2026-05-19T20:32:49.967975Z",
     "shell.execute_reply": "2026-05-19T20:32:49.967433Z"
    }
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "\n",
      "PDF 1 with a yield depending on M:\n"
     ]
    },
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "input_line_72:2:3: error: use of undeclared identifier 'pdf1'\n",
      " (pdf1->Print(\"T\"))\n",
      "  ^\n",
      "Error in <HandleInterpreterException>: Error evaluating expression (pdf1->Print(\"T\"))\n",
      "Execution of your code was aborted.\n"
     ]
    }
   ],
   "source": [
    "std::cout << \"\\nPDF 1 with a yield depending on M:\" << std::endl;\n",
    "pdf1->Print(\"T\");\n",
    "std::cout << \"\\nPDF 2 with a yield depending on M:\" << std::endl;\n",
    "pdf2->Print(\"T\");\n",
    "std::cout << \"\\nPDF 3 with a free yield:\" << std::endl;\n",
    "pdf3->Print(\"T\");\n",
    "\n",
    "std::cout << \"\\nThe following leaves have been created automatically while customising:\" << std::endl;\n",
    "newLeaves.Print(\"V\");"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "0ec1f19d",
   "metadata": {},
   "source": [
    "If we needed to set reasonable values for the means of the gaussians, this could be done as follows:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "id": "ac9587ec",
   "metadata": {
    "collapsed": false,
    "execution": {
     "iopub.execute_input": "2026-05-19T20:32:49.969466Z",
     "iopub.status.busy": "2026-05-19T20:32:49.969354Z",
     "iopub.status.idle": "2026-05-19T20:32:50.174977Z",
     "shell.execute_reply": "2026-05-19T20:32:50.174493Z"
    }
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[#0] ERROR:InputArguments -- RooArgSet::operator[]() ERROR: no element named meanG_Sample1 in set\n"
     ]
    }
   ],
   "source": [
    "auto& meanG1 = static_cast<RooRealVar&>(allCustomiserNodes[\"meanG_Sample1\"]);\n",
    "meanG1.setVal(200);\n",
    "auto& meanG2 = static_cast<RooRealVar&>(allCustomiserNodes[\"meanG_Sample2\"]);\n",
    "meanG2.setVal(300);\n",
    "\n",
    "std::cout << \"\\nThe following leaves have been used while customising\"\n",
    "  << \"\\n\\t(partial overlap with the set of automatically created leaves.\"\n",
    "  << \"\\n\\ta new customiser for a different PDF could reuse them if necessary.):\" << std::endl;\n",
    "allCustomiserNodes.Print(\"V\");"
   ]
  }
 ],
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