Language reference
Log (natural logarithm)
Syntax
Log(<number>)
π Log(value) → log_value (Measurements)Description
Log returns the natural logarithm (base e) of a number. It is used to compress wide-ranging values onto a smaller scale and in growth/decay and statistical calculations.
Technical Description
Log(x: NUMBER) → NUMBER. Returns ln(x) (Math.log). The argument must be positive (else an evaluation error). NULL input returns NULL. PURE, DETERMINISTIC. Floating-point result.
Examples
Log-transform a measurement:
π Log(value) → log_value (Measurements)PROJECT Log(value) -> log_value (Measurements)Filter on a log-scaled threshold:
σ Log(amount) > 10 (Transactions)SELECT Log(amount) > 10 (Transactions)Limitations
Errors on a non-positive argument (x ≤ 0). NUMBER only; NULL in → NULL out. This is the natural log (base e); divide by Log(base) for other bases.
Alternatives
Exp is the inverse (e^x). For log base 10, use Log(x) / Log(10).