Plotly · Class

go.Scatterpolar

go.Scatterpolar is Plotly's generic polar scatter trace. Pair radial coordinates (r) with angular coordinates (theta) and optionally render markers, lines, or a filled region.

How it works

go.Scatterpolar creates a generic polar scatter trace. Supply radial coordinates with r and angular coordinates with theta, then choose trace rendering such as markers, lines, or a filled region.

Syntax

go.Scatterpolar(r=None, theta=None, mode=None, fill=None, **kwargs)

Parameters

Name	Type	Description
`r`	`array-like`	Radial coordinates for the trace's points; the documentation's examples pass a sequence of numeric values.
`theta`	`array-like`	Angular coordinates for the trace's points; examples use numeric angles or categorical labels.
`mode`	`string`	Controls how the trace is rendered, such as markers or lines.
`fill`	`string`	Controls whether and how the trace area is filled.

Returns

A Plotly Scatterpolar trace object.

Key points

Import the class from plotly.graph_objects when you need a lower-level polar scatter trace.
The r property contains radial data points, defining each point's distance from the center.
The theta property contains angular coordinates corresponding positionally to the radial values.
Configure the polar radial axis in the figure layout and make it visible when the chart needs radial scale guidance.

Common mistakes

For radar charts, angular values can be categorical labels rather than numeric angles.

Example: Filled radar chart

import plotly.graph_objects as go

fig = go.Figure(go.Scatterpolar(
    r=[1, 5, 2, 2, 3],
    theta=['processing cost', 'mechanical properties', 'chemical stability', 'thermal stability', 'device integration'],
    fill='toself'
))
fig.update_layout(
    polar=dict(radialaxis=dict(visible=True)),
    showlegend=False
)
fig.show()

Creates a filled radar-style polar trace from radial values and categorical angular labels.

When to use it

Custom polar scatter plots

You need direct control over a polar trace beyond Plotly Express.

Radar charts

You want a radar or spider chart with category labels around the angular axis.

Multi-series polar comparisons

You need to compare multiple radial series on one polar figure.

Interview questions

QWhen would you choose go.Scatterpolar?

Use go.Scatterpolar when Plotly Express is not a suitable starting point. Construct it as a trace, commonly with r for radial values and theta for angular coordinates, then place it in a go.Figure.

Follow-up: How would you create a radar chart? Use categorical angular labels and set fill='toself' to close and fill the polygon.

QWhat do r and theta represent?

The r array supplies distances from the polar origin, while theta supplies angular positions. The example documentation combines numeric radial values with numeric degree angles for a marker-only polar scatter.

Follow-up: How can the same trace represent a radar chart? Replace numeric angular positions with category labels and use a closed fill.

QHow do you build a radar-style chart with this class?

A radar chart can be made with a polar chart using categorical angular variables. In the documented example, fill='toself' fills the area enclosed by the trace, and the polar radial axis is made visible through layout configuration.

Follow-up: How can you display more than one radar series? Add multiple go.Scatterpolar traces to the figure, each with its own r values and shared category labels.

plotly.graph_objects.Figure
px.scatter_polar
px.line_polar

Source: Polar charts in Python - Plotly. Checked 2026-10-15.