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   "source": [
    "<div style='background-image: url(\"../share/baku.jpg\") ; padding: 0px ; background-size: cover ; border-radius: 15px ; height: 250px; background-position: 0% 80%'>\n",
    "    <div style=\"float: right ; margin: 50px ; padding: 20px ; background: rgba(255 , 255 , 255 , 0.9) ; width: 50% ; height: 150px\">\n",
    "        <div style=\"position: relative ; top: 50% ; transform: translatey(-50%)\">\n",
    "            <div style=\"font-size: xx-large ; font-weight: 900 ; color: rgba(0 , 0 , 0 , 0.9) ; line-height: 100%\">ObsPy Tutorial</div>\n",
    "            <div style=\"font-size: large ; padding-top: 20px ; color: rgba(0 , 0 , 0 , 0.7)\">Handling Event Metadata</div>\n",
    "        </div>\n",
    "    </div>\n",
    "</div>\n",
    "image: User:Abbaszade656 / Wikimedia Commons / <a href=\"http://creativecommons.org/licenses/by-sa/4.0/\">CC-BY-SA-4.0</a>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Workshop for the \"Training in Network Management Systems and Analytical Tools for Seismic\"\n",
    "### Baku, October 2018\n",
    "\n",
    "Seismo-Live: http://seismo-live.org\n",
    "\n",
    "##### Authors:\n",
    "* Lion Krischer ([@krischer](https://github.com/krischer))\n",
    "* Tobias Megies ([@megies](https://github.com/megies))\n",
    "---"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "![](images/obspy_logo_full_524x179px.png)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "%matplotlib inline\n",
    "from __future__ import print_function\n",
    "import matplotlib.pyplot as plt\n",
    "plt.style.use('ggplot')\n",
    "plt.rcParams['figure.figsize'] = 12, 8"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- for event metadata, the de-facto standard is [QuakeML (an xml document structure)](https://quake.ethz.ch/quakeml/)\n",
    "- QuakeML files can be read using **`read_events()`**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import obspy\n",
    "\n",
    "catalog = obspy.read_events(\"./data/south_napa_with_some_aftershocks.xml\")\n",
    "print(catalog)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- **`read_events()`** function returns a **`Catalog`** object, which is\n",
    "a collection of **`Event`** objects."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(type(catalog))\n",
    "print(type(catalog[0]))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "event = catalog[0]\n",
    "print(event)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- Event objects are again collections of other resources.\n",
    "- the nested ObsPy Event class structure (Catalog/Event/Origin/Magnitude/FocalMechanism/...) is closely modelled after QuakeML\n",
    "<img src=\"images/Event.svg\" width=90%>"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(type(event.origins))\n",
    "print(type(event.origins[0]))\n",
    "print(event.origins[0])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(type(event.magnitudes))\n",
    "print(type(event.magnitudes[0]))\n",
    "print(event.magnitudes[0])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "# try event.<Tab> to get an idea what \"children\" elements event has"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- The Catalog object contains some convenience methods to make\n",
    "working with events easier.\n",
    "- for example, the included events can be filtered with various keys."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "largest_magnitude_events = catalog.filter(\"magnitude >= 4.0\")\n",
    "print(largest_magnitude_events)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- There is a basic preview plot using the matplotlib basemap module."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "catalog.plot(projection=\"local\", resolution=\"i\", label=\"magnitude\");"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- a (modified) Catalog can be output to file in a number of different formats."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "largest_magnitude_events.write(\"/tmp/large_events.xml\", format=\"QUAKEML\")\n",
    "!ls -l /tmp/large_events.xml"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- the event type classes can be used to build up Events/Catalogs/Picks/.. from scratch in custom processing work flows and to share them with other researchers in the de facto standard format QuakeML"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from obspy import UTCDateTime\n",
    "from obspy.core.event import Catalog, Event, Origin, Magnitude\n",
    "from obspy.geodetics import FlinnEngdahl\n",
    "\n",
    "cat = Catalog()\n",
    "cat.description = \"Just a fictitious toy example catalog built from scratch\"\n",
    "\n",
    "e = Event()\n",
    "e.event_type = \"not existing\"\n",
    "\n",
    "o = Origin()\n",
    "o.time = UTCDateTime(2014, 2, 23, 18, 0, 0)\n",
    "o.latitude = 47.6\n",
    "o.longitude = 12.0\n",
    "o.depth = 10000\n",
    "o.depth_type = \"operator assigned\"\n",
    "o.evaluation_mode = \"manual\"\n",
    "o.evaluation_status = \"preliminary\"\n",
    "o.region = FlinnEngdahl().get_region(o.longitude, o.latitude)\n",
    "\n",
    "m = Magnitude()\n",
    "m.mag = 7.2\n",
    "m.magnitude_type = \"Mw\"\n",
    "\n",
    "m2 = Magnitude()\n",
    "m2.mag = 7.4\n",
    "m2.magnitude_type = \"Ms\"\n",
    "\n",
    "# also included could be: custom picks, amplitude measurements, station magnitudes,\n",
    "# focal mechanisms, moment tensors, ...\n",
    "\n",
    "# make associations, put everything together\n",
    "cat.append(e)\n",
    "e.origins = [o]\n",
    "e.magnitudes = [m, m2]\n",
    "m.origin_id = o.resource_id\n",
    "m2.origin_id = o.resource_id\n",
    "\n",
    "print(cat)\n",
    "cat.write(\"/tmp/my_custom_events.xml\", format=\"QUAKEML\")\n",
    "!cat /tmp/my_custom_events.xml"
   ]
  }
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