{
"cells": [
{
"cell_type": "markdown",
"id": "51fa0a0b",
"metadata": {},
"source": [
"# rf706_histpdf\n",
"Special pdf's: histogram based pdfs and functions\n",
"\n",
"\n",
"\n",
"\n",
"**Author:** Clemens Lange, Wouter Verkerke (C++ version) \n",
"This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, May 19, 2026 at 08:34 PM."
]
},
{
"cell_type": "code",
"execution_count": 1,
"id": "012b5841",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:43.846367Z",
"iopub.status.busy": "2026-05-19T20:34:43.846250Z",
"iopub.status.idle": "2026-05-19T20:34:44.807717Z",
"shell.execute_reply": "2026-05-19T20:34:44.806915Z"
}
},
"outputs": [],
"source": [
"import ROOT"
]
},
{
"cell_type": "markdown",
"id": "b69fece8",
"metadata": {},
"source": [
"Create pdf for sampling\n",
"---------------------------------------------"
]
},
{
"cell_type": "code",
"execution_count": 2,
"id": "b677c9c9",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:44.809551Z",
"iopub.status.busy": "2026-05-19T20:34:44.809413Z",
"iopub.status.idle": "2026-05-19T20:34:45.066475Z",
"shell.execute_reply": "2026-05-19T20:34:45.065694Z"
}
},
"outputs": [],
"source": [
"x = ROOT.RooRealVar(\"x\", \"x\", 0, 20)\n",
"p = ROOT.RooPolynomial(\"p\", \"p\", x, [0.01, -0.01, 0.0004])"
]
},
{
"cell_type": "markdown",
"id": "402bd9ed",
"metadata": {},
"source": [
"Create low stats histogram\n",
"---------------------------------------------------"
]
},
{
"cell_type": "markdown",
"id": "c9b9016c",
"metadata": {},
"source": [
"Sample 500 events from p"
]
},
{
"cell_type": "code",
"execution_count": 3,
"id": "2ba65230",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:45.078510Z",
"iopub.status.busy": "2026-05-19T20:34:45.078369Z",
"iopub.status.idle": "2026-05-19T20:34:45.225616Z",
"shell.execute_reply": "2026-05-19T20:34:45.224859Z"
}
},
"outputs": [],
"source": [
"x.setBins(20)\n",
"data1 = p.generate({x}, 500)"
]
},
{
"cell_type": "markdown",
"id": "d7193c75",
"metadata": {},
"source": [
"Create a binned dataset with 20 bins and 500 events"
]
},
{
"cell_type": "code",
"execution_count": 4,
"id": "c9364899",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:45.227245Z",
"iopub.status.busy": "2026-05-19T20:34:45.227105Z",
"iopub.status.idle": "2026-05-19T20:34:45.340563Z",
"shell.execute_reply": "2026-05-19T20:34:45.339876Z"
}
},
"outputs": [],
"source": [
"hist1 = data1.binnedClone()"
]
},
{
"cell_type": "markdown",
"id": "90a74135",
"metadata": {},
"source": [
"Represent data in dh as pdf in x"
]
},
{
"cell_type": "code",
"execution_count": 5,
"id": "47a6f32b",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:45.342581Z",
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"iopub.status.idle": "2026-05-19T20:34:45.457788Z",
"shell.execute_reply": "2026-05-19T20:34:45.457060Z"
}
},
"outputs": [],
"source": [
"histpdf1 = ROOT.RooHistPdf(\"histpdf1\", \"histpdf1\", {x}, hist1, 0)"
]
},
{
"cell_type": "markdown",
"id": "ab961288",
"metadata": {},
"source": [
"Plot unbinned data and histogram pdf overlaid"
]
},
{
"cell_type": "code",
"execution_count": 6,
"id": "5b807c65",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:45.459871Z",
"iopub.status.busy": "2026-05-19T20:34:45.459740Z",
"iopub.status.idle": "2026-05-19T20:34:45.644126Z",
"shell.execute_reply": "2026-05-19T20:34:45.643542Z"
}
},
"outputs": [
{
"data": {
"text/plain": [
""
]
},
"execution_count": 6,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"frame1 = x.frame(Title=\"Low statistics histogram pdf\", Bins=100)\n",
"data1.plotOn(frame1)\n",
"histpdf1.plotOn(frame1)"
]
},
{
"cell_type": "markdown",
"id": "c22ead33",
"metadata": {},
"source": [
"Create high stats histogram\n",
"-----------------------------------------------------"
]
},
{
"cell_type": "markdown",
"id": "688b607e",
"metadata": {},
"source": [
"Sample 100000 events from p"
]
},
{
"cell_type": "code",
"execution_count": 7,
"id": "03915710",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:45.646321Z",
"iopub.status.busy": "2026-05-19T20:34:45.646196Z",
"iopub.status.idle": "2026-05-19T20:34:45.788127Z",
"shell.execute_reply": "2026-05-19T20:34:45.787565Z"
}
},
"outputs": [],
"source": [
"x.setBins(10)\n",
"data2 = p.generate({x}, 100000)"
]
},
{
"cell_type": "markdown",
"id": "2a0671a9",
"metadata": {},
"source": [
"Create a binned dataset with 10 bins and 100K events"
]
},
{
"cell_type": "code",
"execution_count": 8,
"id": "de724346",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:45.790193Z",
"iopub.status.busy": "2026-05-19T20:34:45.790062Z",
"iopub.status.idle": "2026-05-19T20:34:45.896401Z",
"shell.execute_reply": "2026-05-19T20:34:45.895856Z"
}
},
"outputs": [],
"source": [
"hist2 = data2.binnedClone()"
]
},
{
"cell_type": "markdown",
"id": "586a93f4",
"metadata": {},
"source": [
"Represent data in dh as pdf in x, 2nd order interpolation"
]
},
{
"cell_type": "code",
"execution_count": 9,
"id": "bc023ec2",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:45.898348Z",
"iopub.status.busy": "2026-05-19T20:34:45.898219Z",
"iopub.status.idle": "2026-05-19T20:34:46.001621Z",
"shell.execute_reply": "2026-05-19T20:34:46.000990Z"
}
},
"outputs": [],
"source": [
"histpdf2 = ROOT.RooHistPdf(\"histpdf2\", \"histpdf2\", {x}, hist2, 2)"
]
},
{
"cell_type": "markdown",
"id": "4330e081",
"metadata": {},
"source": [
"Plot unbinned data and histogram pdf overlaid"
]
},
{
"cell_type": "code",
"execution_count": 10,
"id": "ec5cedf3",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:46.003554Z",
"iopub.status.busy": "2026-05-19T20:34:46.003427Z",
"iopub.status.idle": "2026-05-19T20:34:46.249158Z",
"shell.execute_reply": "2026-05-19T20:34:46.248428Z"
}
},
"outputs": [
{
"name": "stderr",
"output_type": "stream",
"text": [
"Info in : png file rf706_histpdf.png has been created\n"
]
}
],
"source": [
"frame2 = x.frame(Title=\"High stats histogram pdf with interpolation\", Bins=100)\n",
"data2.plotOn(frame2)\n",
"histpdf2.plotOn(frame2)\n",
"\n",
"c = ROOT.TCanvas(\"rf706_histpdf\", \"rf706_histpdf\", 800, 400)\n",
"c.Divide(2)\n",
"c.cd(1)\n",
"ROOT.gPad.SetLeftMargin(0.15)\n",
"frame1.GetYaxis().SetTitleOffset(1.4)\n",
"frame1.Draw()\n",
"c.cd(2)\n",
"ROOT.gPad.SetLeftMargin(0.15)\n",
"frame2.GetYaxis().SetTitleOffset(1.8)\n",
"frame2.Draw()\n",
"\n",
"c.SaveAs(\"rf706_histpdf.png\")"
]
},
{
"cell_type": "markdown",
"id": "8717a963",
"metadata": {},
"source": [
"Draw all canvases "
]
},
{
"cell_type": "code",
"execution_count": 11,
"id": "9ac3cd19",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:34:46.251171Z",
"iopub.status.busy": "2026-05-19T20:34:46.251041Z",
"iopub.status.idle": "2026-05-19T20:34:46.433401Z",
"shell.execute_reply": "2026-05-19T20:34:46.432747Z"
}
},
"outputs": [
{
"data": {
"text/html": [
"\n",
"\n",
"\n",
"
\n",
"\n",
"\n",
"\n"
],
"text/plain": [
""
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"from ROOT import gROOT \n",
"gROOT.GetListOfCanvases().Draw()"
]
}
],
"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": "3.12.12"
}
},
"nbformat": 4,
"nbformat_minor": 5
}