Math & Text
log
$log[]
Calculates the natural logarithm (base e) of a number.
Syntax
$log[value]
$log[]
The function $log[] calculates the natural logarithm (denoted as ln), which is the logarithm in base e (≈ 2.71828).
Syntax
$log[value]
Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
value |
number | Yes | The number whose logarithm to calculate. Must be > 0. |
Behavior
- Returns the natural logarithm of the value as a decimal number (double precision).
$log[1]→0(because e^0 = 1).$log[e]→1(because e^1 = e).- For
0or negative numbers, the behavior is undefined (may return-Infinity,NaNor generate an error).
Examples
Logarithm of 1:
$log[1]
→ 0
Logarithm of e (approx.):
$log[2.718281828]
→ ~1
Logarithm of a large number:
$log[1000]
→ 6.907755...
Logarithm of a fraction:
$log[0.5]
→ -0.693147...
Notes
- This is the natural logarithm (base e), not the base 10 logarithm.
- For base 10 logarithm, use inside
$calculate[]:$calculate[log10(value)]. - For a logarithm in an arbitrary base, use the change of base formula:
log_b(a) = ln(a) / ln(b), which translates to$calculate[log(a) / log(b)]. - The inverse function is exponential:
$calculate[exp(value)]. - The precision matches that of a Java
double(~15 significant digits).