LN

All functions > MATH > LN

Returns the natural logarithm (base e) of a number.

Signatures

Returns: Natural logarithm result

LN(number: T) → DOUBLE

Notes

• Only defined for positive numbers (number > 0)
• LN(1) = 0
• LN(e) = 1 where e ≈ 2.718281828459045
• Returns NULL if input is NULL
• Returns negative infinity for LN(0)
• Returns NaN for negative numbers
• Inverse of EXP function: LN(EXP(x)) = x

Examples

SELECT
    f1 := LN(1.0e0),  -- Natural log of 1 is 0
    f2 := LN(2.718281828459045e0),  -- Natural log of e is 1
    f3 := LN(10.0e0),  -- Natural log of 10
    f4 := LN(0.5e0),  -- Natural log less than 1
    f5 := LN(100.0e0)  -- Natural log of 100
;