visualisation improvements (#197)

* add reference to streamlit

* this adds a bit of context about when to use which library

Author: pvgenuchten

workshop/jupyter/content/notebooks/07-visualization.ipynb

@@ -8,10 +8,10 @@
     "When it comes to visualizing geospatial data with/on maps with Python, a great number of tools and techniques\n",
     "are available. In this lesson we will explore several of these:\n",
     "\n",
-    "* [Folium](https://github.com/python-visualization/folium)\n",
-    "* [ipyleaflet](https://ipyleaflet.readthedocs.io)\n",
-    "* [Bokeh](https://bokeh.pydata.org)\n",
-    "* [pydeck](https://pydeck.gl) - optional\n"
+    "* [Folium](#Folium)\n",
+    "* [ipyleaflet](#ipyleaflet)\n",
+    "* [Bokeh](#Bokeh)\n",
+    "* [pydeck](#pydeck)\n"
    ]
   },
   {
@@ -21,14 +21,13 @@
     "## Folium\n",
     "Whenever you visit a website that has some kind of interactive map, it\n",
     "is quite probable that you are witnessing a map that has been made with\n",
-    "a JavaScript library called [Leaflet](http://leafletjs.com). The\n",
-    "other popular library you might encounter is\n",
-    "[OpenLayers](https://openlayers.org).\n",
+    "a JavaScript library called [Leaflet](http://leafletjs.com). Other popular libraries you may encounter are\n",
+    "[OpenLayers](https://openlayers.org) and [maplibre](https://maplibre.org/).\n",
     "\n",
     "The Python module \n",
     "[Folium](https://github.com/python-visualization/folium) makes\n",
     "it possible to visualize data that has been manipulated in Python on an\n",
-    "interactive Leaflet map.\n",
+    "interactive Leaflet map in a jupyter notebook or website generated from python code.\n",
     "\n",
     "### Basics\n",
     "We will start with the most minimal map using the default OpenStreetMap base map.\n",
@@ -158,8 +157,17 @@
    "metadata": {},
    "source": [
     "And [open this map with overlay here](test/07-folium-2.html). \n",
-    "\n",
-    "Much more is possible with Folium, we just scratched the surface here!"
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Folium and Streamlit\n",
+    "Folium can also be [combined with Streamlit](https://folium.streamlit.app/). \n",
+    "[Streamlit](https://streamlit.io) is a platform to create interactive web apps for your python data scripts.\n",
+    "\n"
    ]
   },
   {
@@ -170,12 +178,10 @@
     }
    },
    "source": [
-    "## Interactive maps in the Jupyter notebook with ipyleaflet\n",
-    "ipyleaflet is a Jupyter/Leaflet bridge enabling interactive maps in the Jupyter notebook.\n",
-    "(Although one can always save the results and use these maps in non-Jupyter contexts!).\n",
-    "\n",
-    "`ipyleaflet` is based on [ipywidgets](https://ipywidgets.readthedocs.io).\n",
-    "ipywidgets are interactive HTML widgets for Jupyter notebooks and the IPython kernel.\n",
+    "## ipyleaflet\n",
+    "[ipyleaflet](https://ipyleaflet.readthedocs.io) provides similar functionality as folium, however because\n",
+    "it is based on [ipywidgets](https://ipywidgets.readthedocs.io), it integrates with other components from\n",
+    "the ipywidgets ecosystem (sliders, datagrids, tabs).\n",
     "\n",
     "Links:\n",
     "\n",
@@ -444,8 +450,10 @@
    "source": [
     "## Bokeh\n",
     "\n",
-    "Bokeh is a very powerful framework to produce powerful maps in combination\n",
-    "with data. With Geopandas and Bokeh one can produce nice looking interactive maps like in the image below:\n",
+    "Bokeh is a powerful framework to produce tailored interactive map and data visualisations.\n",
+    "Map features are limited compared to Folium, but there are more options to tailor the behaviour.\n",
+    "Bokeh provides mechanisms to interact with a server side application. With Geopandas and Bokeh\n",
+    "one can produce a nice looking interactive map like in the image below:\n",
     "\n",
     "![Bokeh and Geopandas Example](images/bokeh-example1.jpg)\n",
     "*Interactive Map with Bokeh and GeoPandas - Source: [CSC L6](https://automating-gis-processes.github.io/CSC/lessons/L6/interactive-map-bokeh.html)*\n"
@@ -886,35 +894,64 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## pydeck - OPTIONAL\n",
-    "\n",
-    "[pydeck](https://pydeck.gl/) is a WebGL2-powered, highly performant large-scale data visualization framework.\n",
-    "We leave it you to explore pydeck through [its documentation](https://pydeck.gl/).\n",
-    "\n",
-    "pydeck is part of [deck.gl](https://deck.gl/).\n",
-    "\n",
-    "![From deck.gl repo Example](images/deck.gl.jpg)\n",
-    "\n",
-    "From their [GitHub README](https://github.com/visgl/deck.gl):\n",
+    "## pydeck\n",
     "\n",
-    "*\"deck.gl is designed to simplify high-performance, WebGL-based visualization of large data sets.\n",
-    "Users can quickly get impressive visual results with minimal effort by composing existing layers,\n",
-    "or leverage deck.gl's extensible architecture to address custom needs.*\n",
+    "Up till this point we've looked at 2D data visualisations. With [pydeck](https://pydeck.gl/)\n",
+    "we switch to WebGL-powered data visualization, including 3D and vector tiles.\n",
+    "pydeck is a python wrapper for the [deck.gl](https://deck.gl/) javascript library.\n",
+    "deck.gl visualisations typically use a vector tile background (from [mapbox](https://mapbox.com), [maptiler](https://www.maptiler.com/), or similar)\n",
     "\n",
-    "*deck.gl maps **data** (usually an array of JSON objects) into a stack of visual **layers** - e.g. icons, polygons, texts; and look at them with **views**: e.g. map, first-person, orthographic.*\n",
+    "![Example by deck.gl](images/deck.gl.jpg)\n",
     "\n",
-    "*deck.gl handles a number of challenges out of the box:*\n",
+    "The code snippet below creates a deck.gl view based on some sample data with tooltips.\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 0,
+   "metadata": {
+    "scrolled": true
+   },
+   "outputs": [],
+   "source": [
+    "import pydeck as pdk\n",
+    "import pandas as pd\n",
+    "\n",
+    "# Sample data: 6 locations with population\n",
+    "data = pd.DataFrame({\n",
+    "    'lat': [43.5081, 43.2967, 43.0500, 43.3438, 42.6507, 42.9228],\n",
+    "    'lon': [16.4402, 17.0177, 17.4333, 17.8078, 18.0944, 17.6158],\n",
+    "    'pop': [160000 , 13000, 6500, 105000, 41000, 4000],\n",
+    "    'city': ['Split', 'Makarska', 'Ploče', 'Mostar', 'Dubrovnik', 'Neum']\n",
+    "})\n",
+    "\n",
+    "# Define a scatterplot layer\n",
+    "layer = pdk.Layer(\n",
+    "    'ScatterplotLayer',\n",
+    "    data=data,\n",
+    "    get_position='[lon, lat]',\n",
+    "    get_radius='pop / 10',\n",
+    "    get_fill_color='[180, 0, 200, 140]',\n",
+    "    pickable=True\n",
+    ")\n",
     "\n",
-    "* *Performant rendering and updating of large data sets*\n",
-    "* *Interactive event handling such as picking, highlighting and filtering*\n",
-    "* *Cartographic projections and integration with major basemap providers*\n",
-    "* *A catalog of proven, well-tested layers*\n",
+    "# Define map view\n",
+    "view_state = pdk.ViewState(\n",
+    "    latitude=42.7,\n",
+    "    longitude=16.8,\n",
+    "    zoom=7,\n",
+    "    pitch=30,\n",
+    "    bearing=10\n",
+    ")\n",
     "\n",
-    "*Deck.gl is designed to be highly customizable.*\n",
-    "*All layers come with flexible APIs to allow programmatic control of each aspect of the rendering.*\n",
-    "*All core classes such are easily extendable by the users to address custom use cases.\"*\n",
+    "# Render view\n",
+    "deck = pdk.Deck(\n",
+    "    layers=[layer],\n",
+    "    initial_view_state=view_state,\n",
+    "    tooltip={\"text\": \"{city}\"}\n",
+    ")\n",
     "\n",
-    "deck.gl comes in several flavors (programming languages): JavaScript (`deck.gl`) and Python (`pydeck`)."
+    "deck.show()"
    ]
   },
   {

workshop/jupyter/requirements.txt

@@ -9,5 +9,6 @@ folium
 bokeh==2.4.3
 ipyleaflet
 pandas-bokeh
+pydeck
 pygeometa # >0.7 removed by Just
 matplotlib