Building Radial Plots in Tableau

A comprehensive guide based on analysis of real Tableau Public workbooks.

Overview

Radial plots (also called circular charts or polar charts) display data arranged around a central point. They’re excellent for showing cyclical patterns like seasonal trends, hourly distributions, or year-over-year comparisons.

1. Data Structure Requirements

Your Current Data

Your events.csv contains daily events from 2022-2024 — perfect for radial visualization showing patterns over time.

Data Densification

Radial plots require data densification to create smooth curves. You need to join your data with a “scaffold” table.

Simple Scaffold (for spikes/bars):

Path
0
1

Smooth Curve Scaffold (for continuous lines):

Path
0
1
2
…
100

Create this in Excel or as a separate data source, then use a cross-join (join on a calculated field = 1 on both sides).

2. Derived Fields from Your Date

Create these calculated fields from your date column:

// Year
Year: YEAR([date])

// Day of Year (1-365/366)
Day of Year: DATEPART('dayofyear', [date])

// Month Number
Month: MONTH([date])

// Week of Year
Week: DATEPART('week', [date])

// Day of Week
Day of Week: DATEPART('weekday', [date])

3. Core Calculated Fields

Constants

// Inner circle radius (adjust to taste)
InnerC: 
50

// Outer circle radius (adjust to taste)
OuterC: 
100

// Angle per segment - full circle divided by number of data points
// For daily data (365 days):
PartSizeRad: 
2 * PI() / WINDOW_MAX(MAX([Day of Year]))

// For weekly data (52 weeks):
PartSizeRad: 
2 * PI() / 52

// For monthly data (12 months):
PartSizeRad: 
2 * PI() / 12

Position Calculations

// Rank - determines position around the circle
Rank: 
RANK_UNIQUE(MAX([Day of Year]), 'asc')

// Normalize value to 0-1 range
ValuePart: 
ZN(SUM([events]) / WINDOW_MAX(MAX([events])))

// Angle for each data point (PI/2 offset starts at top)
Angle: 
[PartSizeRad] * [Rank] + PI()/2

X and Y Coordinates

// X coordinate
X: 
COS([Angle]) * ([InnerC] + ([OuterC] - [InnerC]) * [ValuePart])

// Y coordinate
Y: 
SIN([Angle]) * ([InnerC] + ([OuterC] - [InnerC]) * [ValuePart])

For Line Charts with Path (connecting to center)

// X with Path (0 = inner circle, 1 = value position)
X: 
IF [Path] = 0 
THEN COS([Angle]) * [InnerC]
ELSE COS([Angle]) * ([InnerC] + ([OuterC] - [InnerC]) * [ValuePart])
END

// Y with Path
Y: 
IF [Path] = 0 
THEN SIN([Angle]) * [InnerC]
ELSE SIN([Angle]) * ([InnerC] + ([OuterC] - [InnerC]) * [ValuePart])
END

4. Worksheet Setup

Basic Configuration

Setting	Value
Mark Type	Line (or Polygon for filled)
Columns	X
Rows	Y

Shelf Configuration

Shelf	Field	Purpose
Columns	X	Horizontal position
Rows	Y	Vertical position
Path	Path (bin) or Path field	Connects points in order
Detail	Day of Year or Date	Creates individual marks
Color	Year or Month	Distinguishes categories

Axis Settings

Right-click X axis → Edit Axis → Set range to symmetric (e.g., -120 to 120)
Right-click Y axis → Edit Axis → Set range to symmetric (e.g., -120 to 120)
Ensure both axes have the same range for a circular shape
Hide headers and gridlines for clean appearance

5. Table Calculation Settings

Critical Step — Your X and Y calculations must compute correctly:

Right-click on X pill → Compute Using → Select your path/date field
Right-click on Y pill → Compute Using → Select your path/date field

Or use Edit Table Calculation:

Specific Dimensions: Check the fields that define your path
Addressing: The dimension you’re computing across
Partitioning: The dimension you’re computing within

Common Compute Using Options

Chart Type	Compute Using
Daily spiral	Day of Year
Multi-year comparison	Day of Year (partition by Year)
Weekly pattern	Week
Hourly pattern	Hour

6. Visual Variations

Radial Line Chart

Mark type: Line
Shows continuous trend around circle
Good for: Time series, temperature patterns

Radial Bar Chart

Mark type: Polygon or Line with Path
Bars extend from center outward
Good for: Comparing magnitudes

Radial Area Chart

Mark type: Polygon
Filled area from inner circle to value
Good for: Emphasizing volume/quantity

Multi-Ring Spiral

Each year/category as separate ring
Use Year on Color

Adjust radius calculation to offset rings:

Radius Offset:
[InnerC] + (RANK_UNIQUE(MAX([Year]), 'asc') - 1) * 20

7. For Your Events Data

Recommended Approach: Year-over-Year Comparison

Show all three years (2022-2024) as overlapping lines:

Use Day of Year for position around circle
Use Year for color
Each year traces the same 365-day path
Easy to spot seasonal patterns

Alternative: Spiral Timeline

Show all data as one continuous spiral:

Create a sequential index across all dates
Each revolution = one year
Spiral expands outward over time

8. Reference Workbooks

Download these from Tableau Public to see working examples:

Workbook	Author	Type	Link
Arctic Sea Ice Radial	Andy Kriebel	Multi-year line	View
Templates of Radial Charts	Martynas	Multiple types	View
Radial Chart in Tableau	Gurpreet Singh	Tutorial with parameters	View
MLB Franchise History	Bo McCready	Multi-ring	View
Multi-Layered Radial	Ludovic Tavernier	Layered rings	View

9. Troubleshooting

Chart appears as straight line

Check table calculation compute using settings
Ensure Path field is on the Path shelf

Chart is elliptical, not circular

Make X and Y axis ranges identical
Format → Set axis range to fixed symmetric values

Points not connecting properly

Verify Path field is ordered correctly
Check that Rank calculation is working

Values not scaling correctly

Ensure WINDOW_MAX is computing across all marks
Check ValuePart calculation returns 0-1 range

Missing data points

ZN() function handles nulls
Check for null values in source data