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Lines on Maps in Python

How to draw lines, great circles, and contours on maps in Python.

For other geographical and map charts see the maps index page.

Below we show how to create geographical line plots using either plotly express with px.line_geo (for data available as tidy pandas DataFrame) or go.Scattergeo for the generic case.

Lines on Maps with plotly express

In [1]:
import plotly.express as px
gapminder = px.data.gapminder().query("year == 2007")
fig = px.line_geo(gapminder, locations="iso_alpha", 
                  color="continent", # "continent" is one of the columns of gapminder 
                  projection="orthographic")
fig.show()

 Lines on Maps with plotly.graph_objects

US Flight Paths Map

In [2]:
import plotly.graph_objects as go
import pandas as pd

df_airports = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/2011_february_us_airport_traffic.csv')
df_airports.head()

df_flight_paths = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/2011_february_aa_flight_paths.csv')
df_flight_paths.head()

fig = go.Figure()

fig.add_trace(go.Scattergeo(
    locationmode = 'USA-states',
    lon = df_airports['long'],
    lat = df_airports['lat'],
    hoverinfo = 'text',
    text = df_airports['airport'],
    mode = 'markers',
    marker = dict(
        size = 2,
        color = 'rgb(255, 0, 0)',
        line = dict(
            width = 3,
            color = 'rgba(68, 68, 68, 0)'
        )
    )))

flight_paths = []
for i in range(len(df_flight_paths)):
    fig.add_trace(
        go.Scattergeo(
            locationmode = 'USA-states',
            lon = [df_flight_paths['start_lon'][i], df_flight_paths['end_lon'][i]],
            lat = [df_flight_paths['start_lat'][i], df_flight_paths['end_lat'][i]],
            mode = 'lines',
            line = dict(width = 1,color = 'red'),
            opacity = float(df_flight_paths['cnt'][i]) / float(df_flight_paths['cnt'].max()),
        )
    )

fig.update_layout(
    title_text = 'Feb. 2011 American Airline flight paths<br>(Hover for airport names)',
    showlegend = False,
    geo = go.layout.Geo(
        scope = 'north america',
        projection_type = 'azimuthal equal area',
        showland = True,
        landcolor = 'rgb(243, 243, 243)',
        countrycolor = 'rgb(204, 204, 204)',
    ),
)

fig.show()

London to NYC Great Circle

In [3]:
import plotly.graph_objects as go

fig = go.Figure(data=go.Scattergeo(
    lat = [40.7127, 51.5072],
    lon = [-74.0059, 0.1275],
    mode = 'lines',
    line = dict(width = 2, color = 'blue'),
))

fig.update_layout(
    title_text = 'London to NYC Great Circle',
    showlegend = False,
    geo = dict(
        resolution = 50,
        showland = True,
        showlakes = True,
        landcolor = 'rgb(204, 204, 204)',
        countrycolor = 'rgb(204, 204, 204)',
        lakecolor = 'rgb(255, 255, 255)',
        projection_type = "equirectangular",
        coastlinewidth = 2,
        lataxis = dict(
            range = [20, 60],
            showgrid = True,
            dtick = 10
        ),
        lonaxis = dict(
            range = [-100, 20],
            showgrid = True,
            dtick = 20
        ),
    )
)

fig.show()

Contour lines on globe

In [4]:
import plotly.graph_objects as go
import pandas as pd

df = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/globe_contours.csv')
df.head()


scl = ['rgb(213,62,79)', 'rgb(244,109,67)', 'rgb(253,174,97)', \
    'rgb(254,224,139)', 'rgb(255,255,191)', 'rgb(230,245,152)', \
    'rgb(171,221,164)', 'rgb(102,194,165)', 'rgb(50,136,189)'
]
n_colors = len(scl)

fig = go.Figure()

for i, (lat, lon) in enumerate(zip(df.columns[::2], df.columns[1::2])):
    fig.add_trace(go.Scattergeo(
        lon = df[lon],
        lat = df[lat],
        mode = 'lines',
        line = dict(width = 2, color = scl[i % n_colors]
        )))

fig.update_layout(
    title_text = 'Contour lines over globe<br>(Click and drag to rotate)',
    showlegend = False,
    geo = dict(
        showland = True,
        showcountries = True,
        showocean = True,
        countrywidth = 0.5,
        landcolor = 'rgb(230, 145, 56)',
        lakecolor = 'rgb(0, 255, 255)',
        oceancolor = 'rgb(0, 255, 255)',
        projection = dict(
            type = 'orthographic',
            rotation = dict(
                lon = -100,
                lat = 40,
                roll = 0
            )
        ),
        lonaxis = dict(
            showgrid = True,
            gridcolor = 'rgb(102, 102, 102)',
            gridwidth = 0.5
        ),
        lataxis = dict(
            showgrid = True,
            gridcolor = 'rgb(102, 102, 102)',
            gridwidth = 0.5
        )
    )
)

fig.show()

Reference

See https://plot.ly/python/reference/#scattergeo for more information and chart attribute options!