{
  "nbformat": 4,
  "nbformat_minor": 5,
  "metadata": {
    "colab": {
      "provenance": []
    },
    "kernelspec": {
      "name": "python3",
      "display_name": "Python 3"
    },
    "language_info": {
      "name": "python"
    }
  },
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Chapter 1 - Daily Heart Rate Distribution\n",
        "\n",
        "This notebook runs in demo mode by default, using generated minute-level heart-rate data. Replace the demo data cell with a Garmin export or API pull when working with your own data."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {},
      "outputs": [],
      "source": [
        "import numpy as np\n",
        "import pandas as pd\n",
        "\n",
        "np.random.seed(7)\n",
        "minutes = pd.date_range(\"2026-01-01\", periods=24 * 60 * 14, freq=\"min\")\n",
        "hour = minutes.hour.to_numpy()\n",
        "\n",
        "base = 58 + 5 * np.sin(2 * np.pi * (hour - 6) / 24)\n",
        "movement = np.where((hour >= 8) & (hour <= 20), np.random.gamma(1.8, 4.0, len(minutes)), 0)\n",
        "training = np.zeros(len(minutes))\n",
        "for day in range(14):\n",
        "    start = day * 24 * 60 + 17 * 60\n",
        "    duration = 35 + (day % 4) * 10\n",
        "    training[start:start + duration] = np.linspace(35, 80, duration)\n",
        "heart_rate = np.clip(base + movement + training + np.random.normal(0, 3, len(minutes)), 42, 185)\n",
        "\n",
        "hr = pd.DataFrame({\"timestamp\": minutes, \"heart_rate\": heart_rate.round(0).astype(int)})\n",
        "hr.head()"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {},
      "outputs": [],
      "source": [
        "bins = [0, 60, 70, 80, 90, 100, 120, 140, 160, 220]\n",
        "labels = [\"<60\", \"60-69\", \"70-79\", \"80-89\", \"90-99\", \"100-119\", \"120-139\", \"140-159\", \"160+\"]\n",
        "hr[\"zone\"] = pd.cut(hr[\"heart_rate\"], bins=bins, labels=labels, right=False)\n",
        "distribution = (\n",
        "    hr.groupby(\"zone\", observed=False)\n",
        "      .size()\n",
        "      .rename(\"minutes\")\n",
        "      .reset_index()\n",
        ")\n",
        "distribution[\"hours\"] = (distribution[\"minutes\"] / 60).round(1)\n",
        "distribution[\"percent\"] = (distribution[\"minutes\"] / distribution[\"minutes\"].sum() * 100).round(1)\n",
        "distribution"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {},
      "outputs": [],
      "source": [
        "import plotly.express as px\n",
        "\n",
        "fig = px.bar(distribution, x=\"zone\", y=\"hours\", title=\"Daily Life Heart-Rate Distribution\")\n",
        "fig.update_layout(xaxis_title=\"Heart-rate band (bpm)\", yaxis_title=\"Hours across sample\")\n",
        "fig.show()\n",
        "print(\"Notebook completed.\")"
      ]
    }
  ]
}