{
 "cells": [
  {
   "metadata": {},
   "cell_type": "markdown",
   "source": "# Field Calculations",
   "id": "1352f7a09dd0bcb0"
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:27:44.495280267Z",
     "start_time": "2026-05-01T01:27:44.445842745Z"
    }
   },
   "cell_type": "code",
   "source": "import footbridge as ft",
   "id": "70a74488247e76b7",
   "outputs": [],
   "execution_count": 11
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:27:44.541920093Z",
     "start_time": "2026-05-01T01:27:44.495998301Z"
    }
   },
   "cell_type": "code",
   "source": [
    "# large dataset of US National Highway System roads\n",
    "# https://hepgis-usdot.hub.arcgis.com/datasets/dce9f09392eb474c8ad8e6a78416279b_0\n",
    "gdb_file = \"NHS.gdb\""
   ],
   "id": "40256b93c77f7073",
   "outputs": [],
   "execution_count": 12
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:27:56.525044543Z",
     "start_time": "2026-05-01T01:27:44.542656710Z"
    }
   },
   "cell_type": "code",
   "source": "gdb = ft.GeoDatabase(gdb_file)",
   "id": "ae69d18f3691773a",
   "outputs": [],
   "execution_count": 13
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:27:56.622908717Z",
     "start_time": "2026-05-01T01:27:56.576589846Z"
    }
   },
   "cell_type": "code",
   "source": "fc = gdb[0]",
   "id": "9c11a257cbc298f2",
   "outputs": [],
   "execution_count": 14
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:27:56.671005534Z",
     "start_time": "2026-05-01T01:27:56.623681419Z"
    }
   },
   "cell_type": "code",
   "source": "fc.list_fields()",
   "id": "ef8b9e89db39c726",
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['ObjectID',\n",
       " 'VERSION',\n",
       " 'YEAR',\n",
       " 'STFIPS',\n",
       " 'CTFIPS',\n",
       " 'ROUTEID',\n",
       " 'BEGINPOINT',\n",
       " 'ENDPOINT',\n",
       " 'SIGN1',\n",
       " 'SIGNT1',\n",
       " 'SIGNN1',\n",
       " 'LNAME',\n",
       " 'NHS',\n",
       " 'STATUS',\n",
       " 'FACID',\n",
       " 'CONNID',\n",
       " 'CONNDES',\n",
       " 'CONNMILES',\n",
       " 'ACLASS',\n",
       " 'FCLASS',\n",
       " 'FACILITYT',\n",
       " 'THROUGH_LA',\n",
       " 'SPEED_LIMI',\n",
       " 'OWNERSHIP',\n",
       " 'URBANCODE',\n",
       " 'AADT',\n",
       " 'AADT_COM',\n",
       " 'AADT_SINGL',\n",
       " 'FUT_AADT',\n",
       " 'FUT_YEAR',\n",
       " 'MILES',\n",
       " 'UPDATE_DAT',\n",
       " 'NHS_ACTION',\n",
       " 'FILE_NAME',\n",
       " 'SHAPE_Length',\n",
       " 'geometry']"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "execution_count": 15
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:27:56.722021108Z",
     "start_time": "2026-05-01T01:27:56.671637956Z"
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   },
   "cell_type": "code",
   "source": "fc.select_columns(\"VERSION\", geometry=False).head(silent=True)",
   "id": "8931f9eab93582f2",
   "outputs": [
    {
     "data": {
      "text/plain": [
       "             VERSION\n",
       "ObjectID            \n",
       "0         2025.08.08\n",
       "1         2025.08.08\n",
       "2         2025.08.08\n",
       "3         2025.08.08\n",
       "4         2025.08.08\n",
       "5         2025.08.08\n",
       "6         2025.08.08\n",
       "7         2025.08.08\n",
       "8         2025.08.08\n",
       "9         2025.08.08"
      ],
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       "      <th></th>\n",
       "      <th>VERSION</th>\n",
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       "      <td>2025.08.08</td>\n",
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       "      <td>2025.08.08</td>\n",
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       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>2025.08.08</td>\n",
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       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>2025.08.08</td>\n",
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       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>2025.08.08</td>\n",
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       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>2025.08.08</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>2025.08.08</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>2025.08.08</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "execution_count": 16
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:27:56.995183001Z",
     "start_time": "2026-05-01T01:27:56.722753226Z"
    }
   },
   "cell_type": "code",
   "source": [
    "# change all the rows in the \"VERSION\" column to \"2025\"\n",
    "fc.calculate(\"VERSION\", \"2025\")"
   ],
   "id": "778e81d6a600d917",
   "outputs": [],
   "execution_count": 17
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:27:57.108793942Z",
     "start_time": "2026-05-01T01:27:57.059139185Z"
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   },
   "cell_type": "code",
   "source": "fc.select_columns(\"VERSION\", geometry=False).head(silent=True)",
   "id": "1422ed010961bc23",
   "outputs": [
    {
     "data": {
      "text/plain": [
       "         VERSION\n",
       "ObjectID        \n",
       "0           2025\n",
       "1           2025\n",
       "2           2025\n",
       "3           2025\n",
       "4           2025\n",
       "5           2025\n",
       "6           2025\n",
       "7           2025\n",
       "8           2025\n",
       "9           2025"
      ],
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       "      <td>2025</td>\n",
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       "      <td>2025</td>\n",
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       "      <td>2025</td>\n",
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       "      <td>2025</td>\n",
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       "      <td>2025</td>\n",
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       "      <th>8</th>\n",
       "      <td>2025</td>\n",
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       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>2025</td>\n",
       "    </tr>\n",
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       "</table>\n",
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      ]
     },
     "execution_count": 18,
     "metadata": {},
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   ],
   "execution_count": 18
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-05-01T01:28:24.655016383Z",
     "start_time": "2026-05-01T01:27:57.109600605Z"
    }
   },
   "cell_type": "code",
   "source": [
    "fc.calculate(\"km\", \"float($MILES$) * 1.609344\")\n",
    "fc.select_columns((\"MILES\", \"km\"), geometry=False).head(silent=True)"
   ],
   "id": "92b4c367a3862e7d",
   "outputs": [
    {
     "data": {
      "text/plain": [
       "              MILES         km\n",
       "ObjectID                      \n",
       "0         17.912424  28.827252\n",
       "1          0.949648   1.528310\n",
       "2          1.429447   2.300472\n",
       "3          2.889823   4.650719\n",
       "4          0.249906   0.402185\n",
       "5          0.368853   0.593611\n",
       "6         12.455991  20.045974\n",
       "7          7.699296  12.390816\n",
       "8          3.027736   4.872669\n",
       "9          0.160367   0.258086"
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     "execution_count": 19,
     "metadata": {},
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   ],
   "execution_count": 19
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