fix focal notebook imports (#481)

Author: giancastro

docs/source/user_guide/focal.ipynb

@@ -60,10 +60,12 @@
     "W = 800\n",
     "H = 600\n",
     "\n",
-    "cvs = ds.Canvas(plot_width=W, plot_height=H, x_range=(-20e6, 20e6), y_range=(-20e6, 20e6))\n",
+    "cvs = ds.Canvas(\n",
+    "    plot_width=W, plot_height=H, x_range=(-20e6, 20e6), y_range=(-20e6, 20e6)\n",
+    ")\n",
     "terrain = generate_terrain(canvas=cvs)\n",
     "\n",
-    "shade(terrain, cmap=['black', 'white'], how='linear')"
+    "shade(terrain, cmap=[\"black\", \"white\"], how=\"linear\")"
    ]
   },
   {
@@ -89,10 +91,10 @@
     "cvs = ds.Canvas(plot_width=W, plot_height=H, x_range=(-20, 20), y_range=(-20, 20))\n",
     "\n",
     "terrain = generate_terrain(canvas=cvs)\n",
-    "terrain_shaded = shade(terrain, cmap=Elevation, alpha=128, how='linear')\n",
+    "terrain_shaded = shade(terrain, cmap=Elevation, alpha=128, how=\"linear\")\n",
     "\n",
     "illuminated = hillshade(terrain)\n",
-    "illuminated_shaded = shade(illuminated, cmap=['gray', 'white'], alpha=255, how='linear')\n",
+    "illuminated_shaded = shade(illuminated, cmap=[\"gray\", \"white\"], alpha=255, how=\"linear\")\n",
     "\n",
     "stack(illuminated_shaded, terrain_shaded)"
    ]
@@ -127,13 +129,14 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "from xrspatial import convolution\n",
     "from xrspatial import focal\n",
     "\n",
-    "cellsize_x, cellsize_y = focal.calc_cellsize(terrain)\n",
+    "cellsize_x, cellsize_y = convolution.calc_cellsize(terrain)\n",
     "# Use an annulus kernel with a ring at a distance from 25-30 cells away from focal point\n",
     "outer_radius = cellsize_x * 30\n",
     "inner_radius = cellsize_x * 25\n",
-    "kernel = focal.annulus_kernel(cellsize_x, cellsize_y, outer_radius, inner_radius)\n",
+    "kernel = convolution.annulus_kernel(cellsize_x, cellsize_y, outer_radius, inner_radius)\n",
     "tpi = terrain - focal.apply(terrain, kernel)\n",
     "tpi_terrain = hillshade(terrain - focal.apply(terrain, kernel))\n",
     "tpi_terrain_shaded = shade(\n",
@@ -211,7 +214,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.8"
+   "version": "3.8.10"
   }
  },
  "nbformat": 4,