{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import (\n",
    "    \"log\"\n",
    "    \"image/color\"\n",
    "    \n",
    "    \"go-hep.org/x/hep/hbook\"\n",
    "    \"golang.org/x/exp/rand\"\n",
    "    \"gonum.org/v1/gonum/stat/distuv\"\n",
    ")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "npoints := 10000"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// Create a normal distribution.\n",
    "dist := distuv.Normal{\n",
    "    Mu:    0,\n",
    "    Sigma: 1,\n",
    "    Src:   rand.New(rand.NewSource(0)),\n",
    "}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// Draw some random values from the standard\n",
    "// normal distribution.\n",
    "hist := hbook.NewH1D(100, -4, +4)\n",
    "for i := 0; i < npoints; i++ {\n",
    "    v := dist.Rand()\n",
    "    hist.Fill(v, 1)\n",
    "}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// normalize histogram\n",
    "area := 0.0\n",
    "for _, bin := range hist.Binning().Bins() {\n",
    "    area += bin.SumW() * bin.XWidth()\n",
    "}\n",
    "hist.Scale(1 / area)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "printf(\"entries:  %v\\n\", hist.Entries())\n",
    "printf(\"x-mean:   %v\\n\", hist.XMean())\n",
    "printf(\"x-stddev: %v\\n\", hist.XStdDev())"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import (\n",
    "    \"go-hep.org/x/hep/hplot\"\n",
    "    \"gonum.org/v1/plot/vg\"\n",
    ")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// Make a plot and set its title.\n",
    "p := hplot.New()\n",
    "p.Title.Text = \"Histogram\"\n",
    "p.X.Label.Text = \"X\"\n",
    "p.Y.Label.Text = \"Y\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// Create a histogram of our values drawn\n",
    "// from the standard normal.\n",
    "h := hplot.NewH1D(hist)\n",
    "h.Infos.Style = hplot.HInfoSummary\n",
    "p.Add(h)\n",
    "\n",
    "// The normal distribution function\n",
    "norm := hplot.NewFunction(dist.Prob)\n",
    "norm.Color = color.RGBA{R: 0xff, A: 255}\n",
    "norm.Width = vg.Length(2)\n",
    "p.Add(norm)\n",
    "\n",
    "// draw a grid\n",
    "p.Add(hplot.NewGrid())"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "hplot.Show(p, 640, -1, \"png\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// Draw some random values from a shifted standard normal\n",
    "// normal distribution.\n",
    "h1 := hbook.NewH1D(100, -5, +5)\n",
    "h2 := hbook.NewH1D(100, -5, +5)\n",
    "for i := 0; i < npoints; i++ {\n",
    "    h1.Fill(rand.NormFloat64()-1, 1.0)\n",
    "    h2.Fill(rand.NormFloat64()+1, 1.3)\n",
    "}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "p = hplot.New()\n",
    "p.Title.Text = \"Histos + color blending\"\n",
    "p.X.Label.Text = \"x\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "hh1 := hplot.NewH1D(h1)\n",
    "hh1.FillColor = color.NRGBA{R:0xff, A:128}\n",
    "hh1.Color = color.Black"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "hh2 := hplot.NewH1D(h2)\n",
    "hh2.FillColor = color.NRGBA{B:0xff, A:128}\n",
    "hh2.Color = color.Black"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "p.Add(hh1, hh2, hplot.NewGrid())\n",
    "hplot.Show(p, 640, -1, \"png\")"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Go",
   "language": "go",
   "name": "go"
  },
  "language_info": {
   "codemirror_mode": "go",
   "file_extension": ".go",
   "mimetype": "",
   "name": "go",
   "nbconvert_exporter": "",
   "pygments_lexer": "go",
   "version": "unreleased"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}