LOG1P

​

Syntax

​

Scalar

log1p(value)

​

Arguments

​

Returns

• Type: DOUBLE
• Possible values: Real logarithms for input greater than -1; NaN and positive infinity propagate.
• NULL behavior: Returns NULL for NULL input or input less than or equal to -1, including negative infinity.

​

Properties

• Approximation bound: No fixed maximum error is guaranteed.

​

Usage notes

• The calculation preserves precision for values close to zero.
• INTEGER and INT mean the same type; STRING means VARCHAR text. NULL can be used with a supported type. Cast NULL explicitly when its type would otherwise be unclear.
• Exact result: Floating-point computation can round the mathematical result.

​

Examples

​

Zero, domain boundary and NULL input

SELECT log1p(0) AS "value", log1p(-1) AS domain_boundary, log1p(CAST(NULL AS DOUBLE)) AS null_value;

​

Positive and negative inputs

SELECT round(log1p(CAST(1 AS DOUBLE)), 6) AS positive_input, round(log1p(CAST(-0.5 AS DOUBLE)), 6) AS negative_input;