log()

The log() function returns the natural logarithm (base e) of the input value.

Syntax

Parameters

NUM_EXPR

A numeric expression whose natural logarithm is to be computed.

Description

The log() function applies Math.log() 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 negative infinity (-Infinity) if the input is 0. Returns NaN if the input is negative.

Error codes

N/A

Usage examples

1. Calculate the natural logarithm.

   json "{'val': 10}" | eval result = log(val)
   | # result: 2.302585092994046
   

2. Calculate the natural logarithm of e.

   json "{'val': 2.718281828459045}" | eval result = log(val)
   | # result: 1.0
   

3. NULL input

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

Compatibility

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