set-raster-nodata.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "/Users/mitchellgritts/Documents/projects/vp-airflow/dags\n"
     ]
    }
   ],
   "source": [
    "cd ../.."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "\n",
    "import os\n",
    "import numpy as np\n",
    "import rasterio\n",
    "from rasterio.transform import Affine\n",
    "from rasterio import CRS\n",
    "from common.bounding_box import BoundingBox\n",
    "\n",
    "downloads_dir = \"/Users/mitchellgritts/Downloads\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "# make raster helper work locally\n",
    "def make_raster(\n",
    "    filename: str,\n",
    "    data = np.ones((3, 3), dtype=np.float32),\n",
    "    profile = None,\n",
    "    resolution = (5, -5),\n",
    "    bounding_box: BoundingBox = None,\n",
    "    crs = None,\n",
    ") -> str:\n",
    "    raster_path = os.path.join(downloads_dir, filename)\n",
    "\n",
    "    # If no profile is provided, create a default profile\n",
    "    default_profile = {\n",
    "        \"count\": 1,\n",
    "        \"compress\": \"lzw\",\n",
    "        \"crs\": CRS.from_epsg(3310),\n",
    "        \"driver\": \"GTiff\",\n",
    "        \"dtype\": data.dtype,\n",
    "        \"height\": data.shape[0],\n",
    "        \"interleave\": \"band\",\n",
    "        \"nodata\": 0.0,\n",
    "        \"tiled\": False,\n",
    "        \"transform\": Affine.translation(0, 5)\n",
    "        * Affine.scale(resolution[0], resolution[1]),\n",
    "        \"width\": data.shape[1],\n",
    "    }\n",
    "\n",
    "    if profile is None:\n",
    "        new_profile = default_profile\n",
    "    else:\n",
    "        new_profile = {**default_profile, **profile}\n",
    "\n",
    "    # If bounds are provided, overwrite the transform\n",
    "    if bounding_box is not None:\n",
    "        new_profile[\"transform\"] = rasterio.transform.from_bounds(\n",
    "            *bounding_box.to_rasterio(), new_profile[\"width\"], new_profile[\"height\"]\n",
    "        )\n",
    "\n",
    "    # If a CRS is provided, update the profile\n",
    "    if crs is not None:\n",
    "        new_profile[\"crs\"] = crs\n",
    "\n",
    "    with rasterio.open(raster_path, \"w\", **new_profile) as dst:\n",
    "        if new_profile[\"count\"] > 1:\n",
    "            dst.write(data)  # handles multiband writes\n",
    "        else:\n",
    "            dst.write(data, 1)\n",
    "    return str(raster_path)\n",
    "\n",
    "# ref_raster = make_raster(\"rasterize-ref-raster.tif\", np.ones((4, 4), np.float32), crs=CRS.from_epsg(26910))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "a = np.array([\n",
    "    [0, 1, 0, 1, 0],\n",
    "    [1, 0, 1, 0, 1],\n",
    "    [0, 1, 0, 1, 0],\n",
    "    [1, 0, 1, 0, 1],\n",
    "    [0, 1, 0, 1, 0],\n",
    "], np.int16)\n",
    "\n",
    "ref_raster = make_raster(\"raster-nodata.tif\", a, crs=CRS.from_epsg(26910))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0.0\n",
      "1.0\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "masked_array(\n",
       "  data=[[[0, --, 0, --, 0],\n",
       "         [--, 0, --, 0, --],\n",
       "         [0, --, 0, --, 0],\n",
       "         [--, 0, --, 0, --],\n",
       "         [0, --, 0, --, 0]]],\n",
       "  mask=[[[False,  True, False,  True, False],\n",
       "         [ True, False,  True, False,  True],\n",
       "         [False,  True, False,  True, False],\n",
       "         [ True, False,  True, False,  True],\n",
       "         [False,  True, False,  True, False]]],\n",
       "  fill_value=1,\n",
       "  dtype=int16)"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "with rasterio.open(ref_raster, \"r+\") as src:\n",
    "    print(src.nodata)\n",
    "    # changes no data value\n",
    "    src.nodata = 1  # <- change this value between 1 and 0\n",
    "\n",
    "with rasterio.open(ref_raster) as src:\n",
    "    print(src.nodata)\n",
    "    data = src.read(masked=True)\n",
    "\n",
    "data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1.0\n",
      "32767.0\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "masked_array(\n",
       "  data=[[[0, 1, 0, 1, 0],\n",
       "         [1, 0, 1, 0, 1],\n",
       "         [0, 1, 0, 1, 0],\n",
       "         [1, 0, 1, 0, 1],\n",
       "         [0, 1, 0, 1, 0]]],\n",
       "  mask=[[[False, False, False, False, False],\n",
       "         [False, False, False, False, False],\n",
       "         [False, False, False, False, False],\n",
       "         [False, False, False, False, False],\n",
       "         [False, False, False, False, False]]],\n",
       "  fill_value=32767,\n",
       "  dtype=int16)"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "with rasterio.open(ref_raster, \"r+\") as src:\n",
    "    print(src.nodata)\n",
    "    # changes no data value to proper no data value, but it doesn't exist in the data\n",
    "    src.nodata = 32767\n",
    "\n",
    "with rasterio.open(ref_raster) as src:\n",
    "    print(src.nodata)\n",
    "    data = src.read(masked=True)\n",
    "\n",
    "data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0.0\n"
     ]
    }
   ],
   "source": [
    "# only safe way to do the above, start with a fresh raster\n",
    "ref_raster = make_raster(\"raster-nodata.tif\", a, crs=CRS.from_epsg(26910))\n",
    "\n",
    "with rasterio.open(ref_raster) as src:\n",
    "    print(src.nodata)\n",
    "    src_nodata = src.nodata\n",
    "    src_profile = src.profile\n",
    "    data = src.read() # <- note, not masked\n",
    "\n",
    "# change old nodata to new nodata    \n",
    "data[data == src_nodata] = 32767\n",
    "out_profile = src_profile | {\"nodata\": 32767}\n",
    "\n",
    "with rasterio.open(ref_raster, \"w\", **out_profile) as dst:\n",
    "    dst.write(data)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "32767.0\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "array([[[32767,     1, 32767,     1, 32767],\n",
       "        [    1, 32767,     1, 32767,     1],\n",
       "        [32767,     1, 32767,     1, 32767],\n",
       "        [    1, 32767,     1, 32767,     1],\n",
       "        [32767,     1, 32767,     1, 32767]]], dtype=int16)"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# confirm it worked\n",
    "with rasterio.open(ref_raster) as src:\n",
    "    print(src.nodata)\n",
    "    data = src.read()\n",
    "    maksed_data = src.read(masked=True)\n",
    "\n",
    "data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "masked_array(\n",
       "  data=[[[--, 1, --, 1, --],\n",
       "         [1, --, 1, --, 1],\n",
       "         [--, 1, --, 1, --],\n",
       "         [1, --, 1, --, 1],\n",
       "         [--, 1, --, 1, --]]],\n",
       "  mask=[[[ True, False,  True, False,  True],\n",
       "         [False,  True, False,  True, False],\n",
       "         [ True, False,  True, False,  True],\n",
       "         [False,  True, False,  True, False],\n",
       "         [ True, False,  True, False,  True]]],\n",
       "  fill_value=32767,\n",
       "  dtype=int16)"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "maksed_data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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