Chapter 5:
Plot the map data

Now let’s use the Lat and Lon columns of our CSV file to plot the location data on a map. We’ll use the Scattermapbox Plotly plot to do this, but we’ll first need a Mapbox access token.

Step 1: Get a Mapbox access token

If you don’t already have a Mapbox account, go to to sign up for free and generate a public access token. Add this token to the __init__ method of Form1:

token = '<your-access-token>'

Step 2: Return the map data

Back in our Anvil app, we’ll add another function to the Server Module which will generate the map data.

Create a client-callable function called get_map_data that takes one argument called hour. Let’s set it so that it defaults to 0 if no argument is given. We’ll filter the dataframe based on the hour passed into the function and plot the data onto a map.

def get_map_data(hour=0):
  filtered_data = DATA[DATA['Date/Time'].dt.hour == hour]
  map_data = go.Scattermapbox(lat=filtered_data['Lat'], lon=filtered_data['Lon'], mode='markers')
  return map_data

Step 3: Add data to `self.mapbox_map`

We can now switch back to Form1 and add the map data to the self.mapbox_map plot we added in Step 2. Because the function We’ll also need to add our access token and modify the map’s layout slightly. The __init__ method of the Form should look something like this:

class Form1(Form1Template):

  def __init__(self, **properties):
    # Set Form properties and Data Bindings.
    Plot.templates.default = "rally"

    #create the histogram of uber pickups per hour = go.Bar('create_histogram'))

    #create the map of pickup locations
    token = "<your-token-here>" ='get_map_data')
    #add the access token and center the map on NYC
    self.mapbox_map.layout.mapbox = dict(accesstoken=token, center=dict(lat=40.7128, lon=-74.0060), zoom=10)
    #remove padding from map
    self.mapbox_map.layout.margin = dict(t=0, b=0, l=0, r=0)

Run the app and both plots should now be populated with data

Screenshot of the running app with both the bar chart and map plots populated with data

We now have a static dashboard to display our data. Let’s now modify our code so that the map updates according to user input.

Chapter complete

Congratulations, you've completed this chapter!