Tableau Function: COS

Tableau Function: COS

Category: Number Functions

The COS() function in Tableau calculates the cosine of a given angle (in radians).
It’s a trigonometric function that returns the horizontal component of a unit circle at a specified angle.

Purpose

The primary purpose of the COS() function is to determine the cosine value of an angle — a core operation in geometry, physics, engineering, and spatial analytics.

It helps in analyzing cyclic, periodic, or angular data such as waveforms, rotations, and directional measurements.

Type of Calculation

COS() performs a mathematical trigonometric calculation.
Given an angle in radians, it computes the cosine, which is the ratio of the adjacent side to the hypotenuse in a right-angled triangle:

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Practical Use Cases

• Calculating x-coordinates of points on circular or elliptical paths.

• Converting polar coordinates to Cartesian coordinates.

• Modeling periodic trends such as seasonal cycles or oscillations.

• Signal analysis in sensor or telemetry data.

• Simulating circular motion or direction-based transformations in Tableau.

How It Works?

The COS() function uses the trigonometric cosine rule to determine the horizontal projection of a unit vector rotating around the origin.

Mathematically:

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where θ is the angle in radians.

If you have an angle in degrees, convert it first using the RADIANS() function:

What Does It Return?

• Type: Numeric (floating-point)

• Meaning: Returns the cosine of the specified angle, ranging between −1 and 1.

When Should We Use It?

Use the COS() function when you need to:

• Work with angles, rotations, or directional data.

• Calculate x-axis positions in circular motion.

• Perform spatial transformations (e.g., mapping data to circles).

• Analyze cyclic trends (e.g., time series with daily or seasonal periodicity).

• Build wave-based visualizations (e.g., oscillations or harmonic motion).

Basic Usage

Result: 1

Explanation: The cosine of 0 radians equals 1.

Column Usage

Calculates the cosine for each angle value in the [Angle (radians)] field.
For instance, if [Angle (radians)] = 1.57, Tableau returns approximately 0.0.

Advanced Usage

Convert degrees to radians and compute cosine:

This ensures accurate cosine values when working with degrees instead of radians.

Example Application – Circle Coordinates:

This formula creates the x and y coordinates for points along a circle — useful for polar plots or radial charts.

Tips and Tricks

• Always ensure your angle input is in radians, not degrees.

• Use RADIANS() to convert degrees to radians before applying COS().

• Combine COS() and SIN() to model circular or wave-like patterns.

• Useful in animation or motion-based Tableau visualizations.

• Keep in mind that COS() results are bounded between −1 and 1 — any other result likely indicates input format issues.

Related Functions You Might Need

• SIN(number) – Returns the sine of a number (vertical projection).

• TAN(number) – Returns the tangent of a number.

• ACOS(number) – Returns the inverse cosine (arccosine).

• RADIANS(number) – Converts degrees to radians.

• DEGREES(number) – Converts radians to degrees.

• ATAN2(y, x) – Returns the angle between the x-axis and a point (y, x).

We’ve got plenty of resources to help you master Tableau functions. For more details, check out the official Tableau documentation. Or, if you’re ready for more practice, let’s dive into related functions and build your Tableau skills further!

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