Wednesday, June 29, 2016

Using folium - 6: Layer control (Turn on/off intensity overlay)

In this blog, let's build on the blog from last week that we add a layer control to turn on/off the intensity layer we overlay on the map. All we need is to add two lines to have this control. You can find the script at Qingkai's Github.

In [1]:
import folium
from folium import plugins
from scipy.ndimage import imread
In [2]:
# boundary of the image on the map
min_lon = -123.5617
max_lon = -121.0617
min_lat = 37.382166
max_lat = 39.048834

# create the map
map_ = folium.Map(location=[38.2, -122],
                  tiles='Stamen Terrain', zoom_start = 8)

# read in png file to numpy array
data = imread('./ii_overlay.png')

Intensity = plugins.ImageOverlay(data, opacity=0.8, \
        bounds =[[min_lat, min_lon], [max_lat, max_lon]],\
        attr = 'Shaking Intensity')

# add a name to the layer
Intensity.layer_name = 'Shaking Intensity'

# Overlay the image

# add the layer control