Wind Rose and Polar Bar Charts in Python

How to graph wind rose charts in python. Wind Rose charts display wind speed and direction of a given location.


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Plotly is a free and open-source graphing library for Python. We recommend you read our Getting Started guide for the latest installation or upgrade instructions, then move on to our Plotly Fundamentals tutorials or dive straight in to some Basic Charts tutorials.

Wind Rose Chart with Plotly Express

A wind rose chart (also known as a polar bar chart) is a graphical tool used to visualize how wind speed and direction are typically distributed at a given location. You can use the px.bar_polar function from Plotly Express as below, otherwise use go.Barpolar as explained in the next section.

Plotly Express is the easy-to-use, high-level interface to Plotly, which operates on "tidy" data and produces easy-to-style figures.

In [1]:
import plotly.express as px
df = px.data.wind()
fig = px.bar_polar(df, r="frequency", theta="direction",
                   color="strength", template="plotly_dark",
                   color_discrete_sequence= px.colors.sequential.Plasma_r)
fig.show()

Basic Wind Rose Chart

In [2]:
import plotly.graph_objects as go

fig = go.Figure()

fig.add_trace(go.Barpolar(
    r=[77.5, 72.5, 70.0, 45.0, 22.5, 42.5, 40.0, 62.5],
    name='11-14 m/s',
    marker_color='rgb(106,81,163)'
))
fig.add_trace(go.Barpolar(
    r=[57.5, 50.0, 45.0, 35.0, 20.0, 22.5, 37.5, 55.0],
    name='8-11 m/s',
    marker_color='rgb(158,154,200)'
))
fig.add_trace(go.Barpolar(
    r=[40.0, 30.0, 30.0, 35.0, 7.5, 7.5, 32.5, 40.0],
    name='5-8 m/s',
    marker_color='rgb(203,201,226)'
))
fig.add_trace(go.Barpolar(
    r=[20.0, 7.5, 15.0, 22.5, 2.5, 2.5, 12.5, 22.5],
    name='< 5 m/s',
    marker_color='rgb(242,240,247)'
))

fig.update_traces(text=['North', 'N-E', 'East', 'S-E', 'South', 'S-W', 'West', 'N-W'])
fig.update_layout(
    title='Wind Speed Distribution in Laurel, NE',
    font_size=16,
    legend_font_size=16,
    polar_radialaxis_ticksuffix='%',
    polar_angularaxis_rotation=90,

)
fig.show()

Reference

See https://plotly.com/python/reference/#barpolar for more information and chart attribute options!

What About Dash?

Dash is an open-source framework for building analytical applications, with no Javascript required, and it is tightly integrated with the Plotly graphing library.

Learn about how to install Dash at https://dash.plot.ly/installation.

Everywhere in this page that you see fig.show(), you can display the same figure in a Dash application by passing it to the figure argument of the Graph component from the built-in dash_core_components package like this:

import plotly.graph_objects as go # or plotly.express as px
fig = go.Figure() # or any Plotly Express function e.g. px.bar(...)
# fig.add_trace( ... )
# fig.update_layout( ... )

import dash
import dash_core_components as dcc
import dash_html_components as html

app = dash.Dash()
app.layout = html.Div([
    dcc.Graph(figure=fig)
])

app.run_server(debug=True, use_reloader=False)  # Turn off reloader if inside Jupyter