Log10 (base-10 logarithm)

Syntax

Log10(<number>)

π Log10(value) → magnitude (Measurements)

Description

Log10 returns the logarithm of a number to base 10: the power 10 must be raised to to give it. Log10(1000) is 3. It is the usual way to put a value on an order-of-magnitude scale (decibels, pH, the digit count of a number).

Technical Description

Log10(x: NUMBER) → NUMBER. Returns log₁₀(x) (Math.log10), exact for a power of ten. The argument must be positive (else an evaluation error). NULL input returns NULL. PURE, DETERMINISTIC. Floating-point result. SQL's LOG10(x).

Examples

Order of magnitude of a reading:

π Int(Log10(amount)) → magnitude (Transactions)

PROJECT Int(Log10(amount)) -> magnitude (Transactions)

Limitations

Errors on a non-positive argument (x ≤ 0). NUMBER only; NULL in → NULL out.

Alternatives

Log(10, x) is the same value; Log(b, x) takes any other base, and Log(x) is the natural logarithm.

See Also

log, exp, power