acos()

The acos() function returns the arccosine (inverse cosine) of the input value in radians.

Syntax

Parameters

NUM_EXPR

A numeric expression whose arccosine is to be computed. The value must be between -1 and 1 (inclusive).

Description

The acos() function applies Math.acos() to the input and returns the result as a 64-bit double. If the input is a Number type, it is internally converted using doubleValue() before processing.

Returns null if the input is null or not a number. Returns NaN if the input is less than -1 or greater than 1.

Error codes

N/A

Usage examples

1. Calculate the angle (90 degrees) whose cosine is 0.

   json "{'val': 0}" | eval result = acos(val)
   | # result: 1.5707963267948966
   

2. Calculate the angle (0 degrees) whose cosine is 1.

   json "{'val': 1}" | eval result = acos(val)
   | # result: 0.0
   

3. NULL input

   json "{'val': null}" | eval result = acos(val)
   | # result: null
   

Compatibility

The acos() function is available since before Sonar 4.0.