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   "source": [
    "## Reading from the STAC API with R\n",
    "\n",
    "This quickstart introduces STAC for R users. To use the Planetary Computer's STAC API from Python, see [here](https://planetarycomputer.microsoft.com/docs/quickstarts/reading-stac/).\n",
    "\n",
    "We'll use the [rstac](https://github.com/brazil-data-cube/rstac) library to make requests to the STAC API."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "732a9e0f",
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    {
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     "text": [
      "terra 1.5.12\n",
      "\n",
      "\n",
      "Attaching package: ‘terra’\n",
      "\n",
      "\n",
      "The following objects are masked from ‘package:magrittr’:\n",
      "\n",
      "    extract, inset\n",
      "\n",
      "\n"
     ]
    }
   ],
   "source": [
    "library(rstac)\n",
    "library(magrittr)\n",
    "library(terra)\n",
    "\n",
    "s_obj <- stac(\"https://planetarycomputer.microsoft.com/api/stac/v1/\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "afae50de",
   "metadata": {},
   "source": [
    "We can search for items using `s_obj` and the `stac_search` function:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "856823b0",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "\u001b[1m###STACItemCollection\u001b[22m\n",
      "- \u001b[1mfeatures\u001b[22m (250 item(s)):\n",
      "  - LC09_L2SP_217072_20220515_02_T1\n",
      "  - LC09_L2SP_217071_20220515_02_T2\n",
      "  - LC09_L2SP_219071_20220513_02_T1\n",
      "  - LC09_L2SP_221071_20220511_02_T1\n",
      "  - LC09_L2SP_221070_20220511_02_T1\n",
      "  - LC09_L2SP_221069_20220511_02_T1\n",
      "  - LC08_L2SP_217072_20220507_02_T2\n",
      "  - LC08_L2SP_217071_20220507_02_T1\n",
      "  - LC09_L2SP_218072_20220506_02_T1\n",
      "  - LC09_L2SP_218071_20220506_02_T1\n",
      "  - ... with 240 more feature(s).\n",
      "- \u001b[1massets:\u001b[22m \n",
      "qa, ang, red, blue, drad, emis, emsd, trad, urad, atran, cdist, green, nir08, lwir11, swir16, swir22, coastal, mtl.txt, mtl.xml, mtl.json, qa_pixel, qa_radsat, qa_aerosol, tilejson, rendered_preview\n",
      "- \u001b[1mother field(s):\u001b[22m type, features, links\n"
     ]
    }
   ],
   "source": [
    "it_obj <- s_obj %>% \n",
    "    stac_search(collections = \"landsat-c2-l2\",\n",
    "                bbox = c(-47.02148, -17.35063, -42.53906, -12.98314)) %>%\n",
    "    get_request()\n",
    "\n",
    "print(it_obj)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "55657d45",
   "metadata": {},
   "source": [
    "As detailed in [Using tokens for data access](https://planetarycomputer.microsoft.com/docs/concepts/sas/), accessing *data* from the Planetary Computer typically requires signing the item. `rstac` has built-in support for signing."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "7bc2c07d",
   "metadata": {},
   "outputs": [
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "Warning message:\n",
      "“Items matched not provided.”\n"
     ]
    }
   ],
   "source": [
    "it_obj <- s_obj %>% \n",
    "    stac_search(collections = \"landsat-c2-l2\",\n",
    "                bbox = c(-47.02148, -17.35063, -42.53906, -12.98314)) %>%\n",
    "    get_request() %>%\n",
    "    items_sign(sign_fn = sign_planetary_computer())"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "ec2fdba2",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<img src=\"https://ai4edatasetspublicassets.blob.core.windows.net/assets/notebook-output/quickstarts-reading-stac-r.ipynb/4.png\"/>"
      ],
      "text/plain": [
       "plot without title"
      ]
     },
     "metadata": {
      "image/png": {
       "height": 420,
       "width": 420
      }
     },
     "output_type": "display_data"
    }
   ],
   "source": [
    "url <- paste0(\"/vsicurl/\", it_obj$features[[1]]$assets$blue$href)\n",
    "\n",
    "data <- rast(url)\n",
    "plot(data)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "ddf6735a",
   "metadata": {},
   "source": [
    "### Learn more\n",
    "\n",
    "For more about the Planetary Computer's STAC API, see [Using tokens for data access](https://planetarycomputer.microsoft.com/docs/concepts/sas/) and the [STAC API reference](https://planetarycomputer.microsoft.com/docs/reference/stac/). For more about rstac, see [its documentation](https://rdrr.io/cran/rstac/)."
   ]
  }
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