increase plot resolution

pollution.ipynb

@@ -94,6 +94,15 @@
     "world = geopandas.read_file(geopandas.datasets.get_path('naturalearth_lowres'))"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 70,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "%config InlineBackend.figure_format ='retina'"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,