Dash Interactive Map with Time Slider

Dash Python
1

Hello everyone!

I have enjoyed Dash so far and I think that for python users is really nice to have such a library.
Unfortunately though, I found that there are several limitations when it comes to build a map: I haven’t found a way to build a choropleth map using my own shapefiles (that btw refers to the Netherlands).

I’ ve already visited these forum posts:
Choropleth map in dash,
Create your own choropleth map with custom shapefiles,
Map with custom choropleth areas
Python plotly: how to make a choropleth map with a slider (access grid data issue)
but have’t figured out how this can be realized. I am looking for a hands-on tutorial or at least a long step-by-step explanation! :slight_smile:

My final goal is to build an interactive map with a time slider where a specific percentage of each region in the choropleth map will be displayed and apparently this percentage changes every month…
Do you think that this is doable in Dash? I wouldn’t like using again Shiny for this!
Btw this is how my shapefile looks like:

image
image.png792×211 41.7 KB

2

Here is an example with GeoJSON and the scattermapbox chart type. You can’t use the .shp files directly, you will have to convert your shapefile to GeoJSON

3

Thanks for your reply. Is there any hyperlink in your post? I can’t find the example you talk about…

4

Whoops, sorry, here is the link: https://plot.ly/python/county-level-choropleth/

5

Thank you for your reply, I appreciate!
Unfortunately I can’t understand the example. This is my shape file (converted to geopandas) with the color column that I want to visualize:

image
image.png732×122 5.99 KB

The PC4 column is the the post district region I want to visualize. In matplotlib the map looks like this:

image
image.jpg1286×694 211 KB

I have tried a lot to make the map, but still I can’t understand how to do it. This is my code. First I create a geojson file named shp_brabant_lim.json .

import plotly.plotly as py
from plotly.graph_objs import *

import plotly 
plotly.tools.set_credentials_file(username='USERNAME', api_key='API KEY')
mapbox_access_token = "TOKEN"

scl = [[0.0, 'rgb(242,240,247)'],[0.2, 'rgb(218,218,235)'],[0.4, 'rgb(188,189,220)'],\
            [0.6, 'rgb(158,154,200)'],[0.8, 'rgb(117,107,177)'],[1.0, 'rgb(84,39,143)']]

data = [ dict(
        type='choropleth',
        colorscale = scl,
        autocolorscale = False,
        locations = shp_brabant_lim['PC4'],
        z = shp_brabant_lim['Color'].astype(float),
        text = shp_brabant_lim['Color'],
        marker = dict(
            line = dict (
                color = 'rgb(255,255,255)',
                width = 2
            ) ),
        colorbar = dict(
            title = "Colorscale")
        ) ]


layout = graph_objs.Layout(
    height=600,
    autosize=True,
    hovermode='closest',
    mapbox=dict(
        layers=[
            dict(
                sourcetype = 'geojson',
                source = 'DIRECTORY/shp_brabant_lim.json',
                type = 'fill',
                color = 'rgba(163,22,19,0.8)'
            )
        ],
        accesstoken=mapbox_access_token,
        bearing=0,
        center=dict(
            lat=51.6978,
            lon=-5.3037
        ),
        pitch=0,
        zoom=5.2,
        style='light'
    ),
)

fig = dict(data=data, layout=layout)
py.iplot(fig, filename='Netherlands')

What I get is this:

image
image.png901×436 61.2 KB

I can’t see the reason why the map doesn’t zoom in these coordinates lat=51.6978,lon=-5.3037 and why netherlands is not colored… :frowning:

6

Can you figure out how to create a choropleth map using shapefile in Plotly?
I am struggling to create one. If you finally found how to do it, please show it to me. Thank you

7

No I haven’t found how to do this and I finally used another library. I hope that making choropleth maps using our own shapefiles will be easier in the future.