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An Easy Way to Draw Spider Charts on Tableau — Part I | by BrantTDS | Jul, 2020

>>> Step 2: Create Calculated Fields

№1. [Path]

Create a calculated field

[Path] field tells Tableau the sequencing by which the ‘web’ should walk.

CASE [Quality]
WHEN 'employment' THEN 1
WHEN 'broad' THEN 2
WHEN 'influence' THEN 3
WHEN 'patents' THEN 4
WHEN 'publications' THEN 5
WHEN 'faculty' THEN 6
END

№2. [X-axis]

We’ll use Trigonometry to indicate the direction of each corner of our “spider web”, X-axis is cos value of an angel and Y-axis is sin value of the coordinating angel.

<sin and cos values> by Jonathan Trajkovic

For example, we want ‘employment’ to sit at 30° direction, then X-axis of ‘employment’ is [Score]*cos 30° = [Score]*(SQRT(3)/2) and Y-axis will be [Score]*sin 30° = [Score]*(1/2)

Because we have 6 dimensions dividing 360°, so each dimension will sit at 30°, 90°, 150°, 210°, 270° and 330°.

CASE [Quality]
WHEN 'employment' THEN [Score]*(SQRT(3)/2)
WHEN 'broad' THEN 0
WHEN 'influence' THEN [Score]*(-SQRT(3)/2)
WHEN 'patents' THEN [Score]*(-SQRT(3)/2)
WHEN 'publications' THEN 0
WHEN 'faculty' THEN [Score]*(SQRT(3)/2)
END

№3. [Y-axis]

CASE [Quality]
WHEN 'employment' THEN [Score]*(1/2)
WHEN 'broad' THEN [Score]*1
WHEN 'influence' THEN [Score]*(1/2)
WHEN 'patents' THEN [Score]*(-1/2)
WHEN 'publications' THEN [Score]*(-1)
WHEN 'faculty' THEN [Score]*(-1/2)
END