Timezones and masking (#8)

Adds searching using local time
Refactors code to make tackling #2 easier
Increases speed of execution using cached timezone information using json file
Makes it easier to reuse the ShadowFinder object
Solve duplicate figure in notebook
Rename functions to make symmetry between save load generate more apparent
Increase version to 0.2.0

ShadowFinderColab.ipynb

@@ -15,28 +15,30 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
     "# @title Find a Shadow 🔎 { display-mode: \"form\" }\n",
     "\n",
-    "# @markdown ### ⬅️ Click to find possible locations that match the below information (takes around 10 - 20 seconds)\n",
+    "# @markdown ### ⬅️ Click to find possible locations that match the below information\n",
     "\n",
     "# @markdown Object and shadow are measured at right angles in arbitrary units\n",
     "object_height = 10  # @param {type:\"number\"} Height of object in arbitrary units\n",
     "shadow_length = 8  # @param {type:\"number\"} Length of shadow in arbitrary units\n",
     "\n",
-    "# @markdown Date and time must be given in UTC, using the time format hh:mm:ss\n",
+    "# @markdown Date and time can be given in UTC or local time (set `time type` accordingly), using the time format hh:mm:ss\n",
     "date = \"2024-02-29\"  # @param {type:\"date\"}\n",
     "time = \"12:00:00\"  # @param {type:\"string\"}\n",
+    "time_type = \"utc\"  # @param [\"utc\", \"local\"]\n",
     "\n",
     "# Create output files\n",
     "output = f\"./shadowfinder_{object_height}_{shadow_length}_{date}T{time}.png\"\n",
     "logfile = f\"./shadowfinder_{object_height}_{shadow_length}_{date}T{time}.log\"\n",
     "\n",
     "# Imports\n",
-    "![ ! -f \"deps_loaded\" ] & pip install shadowfinder >> {logfile} 2>&1 & touch deps_loaded\n",
+    "![ ! -f \"timezone_grid.json\" ] && wget https://raw.githubusercontent.com/bellingcat/ShadowFinder/main/timezone_grid.json >> {logfile} 2>&1\n",
+    "![ ! -f \"deps_loaded\" ] && pip install shadowfinder >> {logfile} 2>&1 && touch deps_loaded\n",
     "\n",
     "from shadowfinder.shadowfinder import ShadowFinder\n",
     "import datetime\n",
@@ -48,10 +50,26 @@
     "    datetime_date, datetime_time, tzinfo=datetime.timezone.utc\n",
     ")  # Date and time of interest\n",
     "\n",
-    "finder = ShadowFinder(object_height, shadow_length, date_time)\n",
+    "if \"finder\" not in locals():\n",
+    "    finder = ShadowFinder()\n",
+    "    # check if timezones.npz exists\n",
+    "    try:\n",
+    "        finder.load_timezone_grid()\n",
+    "    except FileNotFoundError:\n",
+    "        finder.generate_timezone_grid()\n",
+    "        finder.save_timezone_grid()\n",
+    "\n",
+    "finder.set_details(object_height, shadow_length, date_time, time_format=time_type)\n",
     "finder.find_shadows()\n",
-    "finder.plot_shadows()"
+    "fig = finder.plot_shadows()"
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {