elasticsearch/docs/reference/query-languages/esql/_snippets/functions/log.md

LOG [esql-log]

Syntax

:::{image} ../../../../../images/log.svg :alt: Embedded :class: text-center :::

Parameters

base

Base of logarithm. If null, the function returns null. If not provided, this function returns the natural logarithm (base e) of a value.

number

Numeric expression. If null, the function returns null.

Description

Returns the logarithm of a value to a base. The input can be any numeric value, the return value is always a double. Logs of zero, negative numbers, and base of one return null as well as a warning.

Supported types

base	number	result
double	double	double
double	integer	double
double	long	double
double	unsigned_long	double
double		double
integer	double	double
integer	integer	double
integer	long	double
integer	unsigned_long	double
integer		double
long	double	double
long	integer	double
long	long	double
long	unsigned_long	double
long		double
unsigned_long	double	double
unsigned_long	integer	double
unsigned_long	long	double
unsigned_long	unsigned_long	double
unsigned_long		double

Examples

ROW base = 2.0, value = 8.0
| EVAL s = LOG(base, value)

base: double	value: double	s:double
2.0	8.0	3.0

row value = 100
| EVAL s = LOG(value);

value: integer	s:double
100	4.605170185988092