{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "89206fb8",
   "metadata": {},
   "source": [
    "# Methods for Boolean arrays\n",
    "\n",
    "Boolean values have been converted to 1 (`True`) and 0 (`False`) in the previous methods. Therefore, `sum` is often used to count the `True` values in a Boolean array:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "72b3a506",
   "metadata": {
    "execution": {
     "iopub.execute_input": "2026-05-21T17:28:03.170094Z",
     "iopub.status.busy": "2026-05-21T17:28:03.169688Z",
     "iopub.status.idle": "2026-05-21T17:28:03.204951Z",
     "shell.execute_reply": "2026-05-21T17:28:03.204603Z",
     "shell.execute_reply.started": "2026-05-21T17:28:03.170074Z"
    }
   },
   "outputs": [],
   "source": [
    "import numpy as np"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "d7908101",
   "metadata": {
    "execution": {
     "iopub.execute_input": "2026-05-21T17:28:03.205391Z",
     "iopub.status.busy": "2026-05-21T17:28:03.205280Z",
     "iopub.status.idle": "2026-05-21T17:28:03.214706Z",
     "shell.execute_reply": "2026-05-21T17:28:03.214441Z",
     "shell.execute_reply.started": "2026-05-21T17:28:03.205383Z"
    }
   },
   "outputs": [],
   "source": [
    "rng = np.random.default_rng()\n",
    "data = rng.normal(size=(7, 3))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "42925e49",
   "metadata": {},
   "source": [
    "Number of positive values:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "afeb251f",
   "metadata": {
    "execution": {
     "iopub.execute_input": "2026-05-21T17:28:03.215073Z",
     "iopub.status.busy": "2026-05-21T17:28:03.214984Z",
     "iopub.status.idle": "2026-05-21T17:28:03.218667Z",
     "shell.execute_reply": "2026-05-21T17:28:03.218340Z",
     "shell.execute_reply.started": "2026-05-21T17:28:03.215065Z"
    }
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "np.int64(12)"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "(data >= 0).sum()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "c73241c0",
   "metadata": {},
   "source": [
    "Number of negative values:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "9f9dd3c4",
   "metadata": {
    "execution": {
     "iopub.execute_input": "2026-05-21T17:28:03.219473Z",
     "iopub.status.busy": "2026-05-21T17:28:03.219350Z",
     "iopub.status.idle": "2026-05-21T17:28:03.221905Z",
     "shell.execute_reply": "2026-05-21T17:28:03.221634Z",
     "shell.execute_reply.started": "2026-05-21T17:28:03.219463Z"
    }
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "np.int64(9)"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "(data < 0).sum()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "e417b114",
   "metadata": {},
   "source": [
    "There are two additional methods, `any` and `all`, which are particularly useful for Boolean arrays:\n",
    "\n",
    "* `any` checks whether one or more values in an array are true\n",
    "* `all` checks whether each value is true"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "e6052cdb",
   "metadata": {
    "execution": {
     "iopub.execute_input": "2026-05-21T17:28:03.222452Z",
     "iopub.status.busy": "2026-05-21T17:28:03.222304Z",
     "iopub.status.idle": "2026-05-21T17:28:03.224595Z",
     "shell.execute_reply": "2026-05-21T17:28:03.224365Z",
     "shell.execute_reply.started": "2026-05-21T17:28:03.222442Z"
    }
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[False, False, False],\n",
       "       [False,  True,  True],\n",
       "       [False, False, False],\n",
       "       [False,  True, False],\n",
       "       [False,  True, False],\n",
       "       [ True,  True,  True],\n",
       "       [ True,  True,  True]])"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "data2 = rng.normal(size=(7, 3))\n",
    "bools = data > data2\n",
    "\n",
    "bools"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "cf41bfea",
   "metadata": {
    "execution": {
     "iopub.execute_input": "2026-05-21T17:28:03.226239Z",
     "iopub.status.busy": "2026-05-21T17:28:03.226153Z",
     "iopub.status.idle": "2026-05-21T17:28:03.228190Z",
     "shell.execute_reply": "2026-05-21T17:28:03.227989Z",
     "shell.execute_reply.started": "2026-05-21T17:28:03.226231Z"
    }
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "np.True_"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "bools.any()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "26dc76d2",
   "metadata": {
    "execution": {
     "iopub.execute_input": "2026-05-21T17:28:03.228466Z",
     "iopub.status.busy": "2026-05-21T17:28:03.228410Z",
     "iopub.status.idle": "2026-05-21T17:28:03.230466Z",
     "shell.execute_reply": "2026-05-21T17:28:03.230246Z",
     "shell.execute_reply.started": "2026-05-21T17:28:03.228459Z"
    }
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "np.False_"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "bools.all()"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3.13 Kernel",
   "language": "python",
   "name": "python313"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.13.0"
  },
  "widgets": {
   "application/vnd.jupyter.widget-state+json": {
    "state": {},
    "version_major": 2,
    "version_minor": 0
   }
  }
 },
 "nbformat": 4,
 "nbformat_minor": 5
}