Daily DAX : Day 351 ACOS

Power BI DAX ACOS Function

Description

The ACOS function in Power BI DAX (Data Analysis Expressions) calculates the arccosine (inverse cosine) of a given number. It returns the angle (in radians) whose cosine is the specified value.

Syntax

ACOS(number)

• number: A numeric value between -1 and 1, representing the cosine of an angle.

Return Value

The angle in radians between 0 and π (approximately 3.14159) whose cosine is the input number. If the input is outside the range [-1, 1], the function returns an error.

Use Case

The ACOS function is commonly used in scenarios involving geometric or trigonometric calculations, such as:

• Calculating angles in spatial data analysis (e.g., in geographic or engineering datasets).
• Analyzing relationships between variables in scientific or statistical models.
• Converting cosine values to angles for visualization or further computation in Power BI reports.

Example

Suppose you have a dataset with a column CosineValue containing the cosine of angles, and you want to calculate the corresponding angles in degrees.

AngleInDegrees = DEGREES(ACOS('Table'[CosineValue]))

If CosineValue is 0.5, the ACOS(0.5) returns approximately 1.047 radians (60 degrees), since the cosine of 60 degrees is 0.5.

Notes

• The input must be between -1 and 1; otherwise, an error occurs.
• Use the DEGREES function to convert the result from radians to degrees if needed.
• Ensure the input column or value is numeric to avoid errors.